COLLADA Format Schema Version 1.3.1 (August 19th, 2005) Copyright 2005 Sony Computer Entertainment Inc. All Rights Reserved The COLLADA element declares the root of the document that comprises some of the content in the COLLADA schema. The COLLADA schema is XML based; therefore, it must have a 'document root element' or document entity to be a well-formed XML document. enable-xmlns The version attribute is the COLLADA schema revision with which the instance document conforms. Required attribute. The accessor element declares an access pattern to one of the array elements: float_array, int_array, Name_array, bool_array, and the generic array element. The accessor element describes access to arrays that are organized in either an interleaved or noninterleaved manner according to the permutations of the offset and stride attributes. The param element describes the output of the accessor element sufficiently to bind that output to consumers of the data stream. The param element may occur zero or more times. The number and order of param elements define the output of the accessor element. Parameters are bound to values in the order they are specified. Parameter ordering is irrelevant to the array data source of the accessor element. This means that no swizzling of the data occurs. The type attribute of the param element, when it is a child of the accessor element, is restricted to the set of array types: int, float, Name, bool, and token. A param element without a name attribute is unbound. This is an indication that the value is not passed to the consumer. The id attribute is a text string containing the unique identifier of the accessor element. This value must be unique within the instance document. Optional attribute. The count attribute indicates the number of times the array is accessed. Required attribute. The offset attribute indicates the index of the first value in the array that is accessed. The default value is 0. Optional attribute. The source attribute indicates the location of the array to access using a URL expression. Required attribute. The stride attribute indicates the number of values to access per count iteration according to the type of data in the source array. The default value is 1, indicating that a single value is accessed. Optional attribute. The stride attribute must have a value equal to or greater then the number of param elements. If there are fewer param elements then indicated by the stride value, the unbound array data source values are skipped. The array element declares the storage for a homogenous array of generic data values. The array element is deprecated in this version of COLLADA and may be removed in the future. The id attribute is a text string containing the unique identifier of the array element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of values in the array. Required attribute. The type attribute indicates the data type, such as floating-point or integer numbers of the values contained in the array. The array may also contain a list of names or tokens conforming to the XML Schema Language derived types xs:Name and xs:token, respectively. Required attribute. The minInclusive attribute indicates the smallest integer value that can be contained in the array. The default value is -2147483648. Optional attribute. The maxInclusive attribute indicates the largest integer value that can be contained in the array. The default value is 2147483647. Optional attribute. The digits attribute indicates the number of significant decimal digits of the float values that can be contained in the array. The default value is 6. Optional attribute. The magnitude attribute indicates the largest exponent of the float values that can be contained in the array. The default value is 38. Optional attribute. The float_array element declares the storage for a homogenous array of floating point values. The float_array element stores the data values for generic use within the COLLADA schema. The arrays themselves are strongly typed but without semantics. They simply describe a sequence of floating point values. The id attribute is a text string containing the unique identifier of this element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of values in the array. Required attribute. The digits attribute indicates the number of significant decimal digits of the float values that can be contained in the array. The default value is 6. Optional attribute. The magnitude attribute indicates the largest exponent of the float values that can be contained in the array. The default value is 38. Optional attribute. The int_array element declares the storage for a homogenous array of integer values. The int_array element stores the data values for generic use within the COLLADA schema. The arrays themselves are strongly typed but without semantics. They simply describe a sequence of integer values. The id attribute is a text string containing the unique identifier of this element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of values in the array. Required attribute. The minInclusive attribute indicates the smallest integer value that can be contained in the array. The default value is -2147483648. Optional attribute. The maxInclusive attribute indicates the largest integer value that can be contained in the array. The default value is 2147483647. Optional attribute. The Name_array element declares the storage for a homogenous array of symbolic name values. The Name_array element stores the data values for generic use within the COLLADA schema. The arrays themselves are strongly typed but without semantics. They simply describe a sequence of XML name values. The id attribute is a text string containing the unique identifier of this element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of values in the array. Required attribute. The bool_array element declares the storage for a homogenous array of Boolean values. The bool_array element stores the data values for generic use within the COLLADA schema. The arrays themselves are strongly typed but without semantics. They simply describe a sequence of XML Boolean values. The id attribute is a text string containing the unique identifier of this element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of values in the array. Required attribute. The input element declares the input semantics of a data source. The input element declares the input connections that a consumer requires. The idx attribute uniquely identifies the input among the set of input elements in scope. Required attribute. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The param element declares parametric information regarding its parent element. The param element describes parameters for generic data flow, program data, and entry points. A functional or programmatical format requires a means for users to specify parametric information. This information represents function parameter (argument) data. The basic declaration of a parameter describes the name, data type, and value data of the parameter. That parameter name identifies it to the function or program. The parameter type indicates the encoding of its value. The parameter value is the actual data. The id attribute is a text string containing the unique identifier of the param element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The flow attribute indicates the direction of data flow. Optional attribute. The semantic attribute is the user-defined meaning of the parameter. Optional attribute. The type attribute indicates the type of the value data. This text string must be understood by the application. Required attribute. The source element declares a data repository that provides values according to the semantics of an input element that refers to it. A data source is a well-known source of information that can be accessed through an established communication channel. The data source provides access methods to the information. These access methods implement various techniques according to the representation of the information. The information may be stored locally as an array of data or a program that generates the data. One of the array elements (array, bool_array, float_array, int_array, or Name_array) may occur zero or more times. The technique element must occur one or more times. Within the technique element, the common profile's accessor elements describe the output of the source element. The output is assembled from the accessor elements in the order they are specified. The asset element may occur zero or one time. The param element may occur zero or more times. The accessor element may occur zero or more times. The combiner element may occur zero or one time. The joints element may occur zero or one time. The program element may occur zero or one time. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the technique. Required attribute. The id attribute is a text string containing the unique identifier of the source element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The mesh element contains vertex and primitive information sufficient to describe basic geometric meshes. Meshes embody a general form of geometric description that primarily includes vertex and primitive information. Vertex information is the set of attributes associated with a point on the surface of the mesh. Each vertex includes data for attributes such as: * Vertex position * Vertex color * Vertex normal * Vertex texture coordinate The mesh also includes a description of how the vertices are organized to form the geometric shape of the mesh. The mesh vertices are collated into geometric primitives such as polygons, triangles, or lines. The source element must occur one or more times as the first elements of mesh. The source element may also occur 0 or more times after the vertices element but before the primitive elements. The source elements provide the bulk of the mesh's vertex data. The vertices element must occur exactly one time. The vertices element describes the meshvertex attributes and establishes their topological identity. The lines element contains line primitives. The linestrips element contains line-strip primitives. The polygons element contains polygon primitives. The triangles element contains triangle primitives. The trifans element contains triangle-fan primitives. The tristrips element contains triangle-strip primitives. The id attribute is a text string containing the unique identifier of the mesh element. This value must be unique within the instance document. Optional attribute. The name attribute is a text string containing the name of the mesh element. Optional attribute. The combiner element declares the aggregation of input streams. The combiner element aggregates input data streams into arrays of data structures. The resulting data structures provide a logical organization of the input streams for higher-level elements. A combiner element contains a sequence of v elements, where 'v' stands for value. Each v element describes the values for an arbitrary number of data structures. Each v element contains indices that reference into the input elements. These indices are position dependent and reference the accessor elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each v element. The input elements are uniquely identified by their idx attribute values. A complete sampling of an aggregate value is completed by gathering one value from each input using the associated index in the v element. The input element must occur two or more times. There must be at least two things to combine. Variable length value element. The indices form the source's output aggregated by the number of inputs. The v element must occur one or more times. The count attribute indicates the number of value elements. Required attribute. The joints element declares the association between joint nodes and attribute data. The joints element associates joint nodes in the scene hierarchy with bind-position matrices in a skin controller. The joint nodes represent the joints of a character skeleton. The skeleton can be resused by different skin controllers. Information particular to a specific skin controller is stored with the skin including the position of the joints at the time the skin was bound them. The input element must occur two or more times because there must be at least two things associated with each other. The input element must not have the idx attribute when it is the child of a joints element. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The id attribute is a text string containing the unique identifier of the joints element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of value elements. Optional attribute. The lines element declares the binding of geometric primitives and vertex attributes for a mesh element. The lines element provides the information needed to bind vertex attributes together and then organize those vertices into individual lines. The vertex array information is supplied in distinct attribute arrays of the mesh element that are then indexed by the lines element. Each line described by the mesh has two vertices. The first line is formed from first and second vertices. The second line is formed from the third and fourth vertices and so on. A lines element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an arbitrary number of individual lines. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @breif Every two indices form a line. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. The count attribute indicates the number of line primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the lines. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The linestrips element declares a binding of geometric primitives and vertex attributes for a mesh element. The linestrips element provides the information needed to bind vertex attributes together and then organize those vertices into connected line-strips. The vertex information is supplied in distinct attribute arrays of the mesh element that are then indexed by the linestrips element. Each line-strip described by the mesh has an arbitrary number of vertices. Each line segment within the line-strip is formed from the current vertex and the preceding vertex. A linestrips element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an arbitrary number of connected line segments. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @brief The first two indices form a line. @brief Each subsequent index extends the line from the previous index. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. The count attribute indicates the number of linestip primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the linestrip. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The polygons element declares the binding of geometric primitives and vertex attributes for a mesh element. The polygons element provides the information needed to bind vertex attributes together and then organize those vertices into individual polygons. (A polygon is a closed plane figure bounded by straight lines or a closed figure on a sphere bounded by arcs of great circles per Merriam-Webster's 10th edition Dictionary). The vertex array information is supplied in distinct attribute arrays of the mesh element that are then indexed by the polygons element. The polygons described can contain arbitrary numbers of vertices. Ideally, they would describe convex shapes, but they may be concave as well. The polygons may also contain holes. The winding order of vertices produced is counter-clockwise and describe the front side of each polygon. If the primitives are assembled without vertex normals then the application may generate per-primitive normals to enable lighting. A polygons element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an individual polygon. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @brief All the indices form a polygon. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. Contour Separator. Primitives after this each describe a hole. A hole in the polygon is indicated by an h element that acts as a contour separator. Any indices following the h element describe the hole, up to the next h element, or the close of the p element. Consequently, h elements are the last data inside a p element. The count attribute indicates the number of polygon primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the polygons. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The triangles element declares the binding of geometric primitives and vertex attributes for a mesh element. The triangles element provides the information needed to bind vertex attributes together and then organize those vertices into individual triangles. The vertex array information is supplied in distinct attribute arrays that are then indexed by the triangles element. Each triangle described by the mesh has three vertices. The first triangle is formed from the first, second, and third vertices. The second triangle is formed from the fourth, fifth, and sixth vertices, and so on. A triangles element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an individual triangle. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @brief Every three indices form a triangle. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. The count attribute indicates the number of triangle primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the triangles. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The trifans element declares the binding of geometric primitives and vertex attributes for a mesh element. The trifans element provides the information needed to bind vertex attributes together and then organize those vertices into connected triangles. The vertex array information is supplied in distinct attribute arrays of the mesh element that are then indexed by the trifans element. Each triangle described by the mesh has three vertices. The first triangle is formed from first, second, and third vertices. Each subsequent triangle is formed from the current vertex, reusing the first and previous vertices. A trifans element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an arbitrary number of connected triangles. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @brief The 1st three indices form a triangle. @brief Each subsequent index forms an additional triangle reusing the first and previous indices. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. The count attribute indicates the number of trifan primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the trifans. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The tristrips element declares the binding of geometric primitives and vertex attributes for a mesh element. The tristrips element provides the information needed to bind vertex attributes together and then organize those vertices into connected triangles. The vertex array information is supplied in distinct attribute arrays of the mesh element that are then indexed by the tristrips element. Each triangle described by the mesh has three vertices. The first triangle is formed from first, second, and third vertices. Each subsequent triangle is formed from the current vertex, reusing the previous two vertices. A tristrips element contains a sequence of p elements, where 'p' stands for primitive. Each p element describes the vertex attributes for an arbitrary number of connected triangles. The param element may occur zero or more times. The input element may occur zero or more times. Primitive element. @brief The 1st three indices form a triangle. @brief Each subsequent index forms an additional triangle reusing the previous two indices. Each p element contains indices that reference into the source elements. These indices are position dependent and reference the contents of the source elements according to the order of the input elements. Here is an example of this: The first index references the first unique input element; the second index references the second unique input element, and so on. This is a simple form of compression that reduces the number of indices required in each p element. The input elements are uniquely identified by their idx attribute values. A complete sampling of a single vertex is completed by gathering one value from each input using the associated index in the p element. The count attribute indicates the number of tristrip primitives. Required attribute. The material attribute refers to the name of a material element, using a URL expression, bound to the tristrips. If the material attribute is not specified then the lighting and shading results are application defined. Optional attribute. The vertices element declares the attributes and identity of mesh-vertices. The vertices element describes mesh-vertices in a mesh geometry or skin controller. The mesh vertices represent the position (identity) of the vertices comprising the mesh and other vertex attributes that are invariant to tessellation. The input element must occur one or more times. One input must have the semantic attribute value of 'POSITION' to establish the topological identity of each vertex in the mesh. An input element may have a semantic attribute whose value is COLOR. These color inputs are RGB vectors (float3). The input element must not have the idx attribute when it is the child of a vertices element. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The id attribute is a text string containing the unique identifier of the vertices element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The count attribute indicates the number of value elements. Optional attribute. The lookat element contains a position and orientation transformation suitable for aiming a camera. Positioning and orienting a camera or object in the scene is often complicated when using a matrix. A lookat transform is an intuitive way to specify an eye position, interest point, and orientation. The lookat element contains a list of 9 floating-point values. As in the OpenGL® Utilities (GLU) implementation, these values are organized into three vectors as follows: * Eye position is given as Px, Py, Pz. * Interest point is given as Ix, Iy, Iz. * Up-axis direction is given as UPx, UPy, UPz. When computing the equivalent (viewing) matrix the interest point is mapped to the negative Z-axis and the eye position to the origin. The up-axis is mapped to the positive Y-axis of the viewing plane. The values are specified in local, object coordinates. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. Matrix transformations embody mathematical changes to points within a coordinate systems or the coordinate system itself. The matrix element contains a 4-by-4 matrix of floating-point values. Matrices in COLLADA are column matrices in the mathematical sense. These matrices are written in rowmajor order to aid the human reader. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The perspective element contains the horizontal field of view of the viewer or 'camera'. Perspective embodies the appearance of objects relative to each other as determined by their distance from a viewer. Computer graphics techniques apply a perspective projection in order to render 3-D objects onto 2-D surfaces to create properly proportioned images on display monitors. As in the RenderMan® specification, the focal point of the operation is at the local origin and the direction is along the z-axis. The focal length of the implied 'camera' is 1.0. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The rotate element contains an angle and a mathematical vector that represents the axis of rotation. Rotations change the orientation of objects in a coordinated system without any translation. Computer graphics techniques apply a rotational transformation in order to orient or otherwise move values with respect to a coordinated system. Conversely, rotation can mean the translation of the coordinated axes about the local origin. The rotate element contains a list of four floating-point values, similar to rotations in the OpenGL® and RenderMan® specification. These values are organized into a column vector [ X, Y, Z ] specifying the axis of rotation and an angle in degrees. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The scale element contains a mathematical vector that represents the relative proportions of the X, Y and Z axes of a coordinated system. Scaling changes the size of objects in a coordinated system without any rotation or translation. Computer graphics techniques apply a scale transformation in order to change the size or proportions of values with respect to a coordinate system axis. The scale element contains a list of three floating-point values. These values are organized into a column vector suitable for matrix composition. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The skew element contains an angle and two mathematical vectors that represent the axis of rotation and the axis of translation. Skew (shear) deforms an object along one axis of a coordinated system. It translates values along the affected axis in a direction that is parallel to that axis. Computer graphics techniques apply a skew or shear transformation in order to deform objects or to correct distortion in images. As in the RenderMan® specification, the skew element contains a list of seven floating-point values. These values are organized into an angle in degrees with two column vectors specifying the axes of rotation and translation. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. The translate element contains a mathematical vector that represents the distance along the X, Y and Z-axes. Translations change the position of objects in a coordinate system without any rotation. Computer graphics techniques apply a translation transformation in order to position or, move values with respect to a coordinate system. Conversely, translation means to move the origin of the local coordinate system. The translate element contains a list of three floating-point values. These values are organized into a column vector suitable for a matrix composition. The sid attribute is a text string value containing the sub-identifier of this element. This value must be unique within the scope of the parent element. Optional attribute. Images embody the graphical representation of a scene or object. The image element declares the storage for the graphical representation of an object. The image element best describes raster image data, but can conceivably handle other forms of imagery. The image element may contain a sequence of hexadecimal, binary octets representing the embedded image data. These values are interpreted at pixel values according to the format attribute. The id attribute is a text string containing the unique identifier of the image element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The source attribute is a valid URL of the image source data. If this attribute is present, then it refers to an image asset that may contain information about the dimensions and format of the image. Optional attribute. The format attribute is a text string value that indicates the image format. Optional attribute. The height attribute is an integer value that indicates the height of the image in pixel units. Optional attribute. The width attribute is an integer value that indicates the width of the image in pixel units. Optional attribute. The depth attribute is an integer value that indicates the depth of the image in pixel units. A 2-D image has a depth of 1, which is also the default value. Optional attribute. The light element declares a light source that illuminates the scene. The light element may be referenced by an instance element to position and orient the light in the scene. A light that is not instantiated in the scene is not active. If the type attribute value is 'DIRECTIONAL' or 'SPOT' then the light's default direction vector in local coordinates is [0,0,-1], pointing down the -Z axis. If the type attribute value is 'POINT' or 'SPOT' then two additional param elements are required: one named 'ATTENUATION', and one named 'ATTENUATION_SCALE', as defined in the COMMON Profile. If the type attribute value is 'SPOT' then all the param elements required by 'POINT' are required. In addition three more param elements are required: one named 'ANGLE' for the cone shape, one named 'FALLOFF', and one named 'FALLOFF_SCALE', as defined in the COMMON Profile. The asset element may occur zero or one time. The child param elements describe the values that the light contributes to a material's computation. The name attribute of one of the param elements must have the value 'COLOR' as it is defined in the COMMON Profile for all light types. The 'COLOR' value of the light element modulates the COMMON Profile parameters named 'AMBIENT', 'DIFFUSE', and 'SPECULAR' of a material element, according to the type attribute value of the light element. If the type attribute value is 'AMBIENT' then the material's 'AMBIENT' parameter is modulated. If the type attribute value is 'DIRECTIONAL', 'POINT', or 'SPOT' then the material's 'DIFFUSE' and 'SPECULAR' parmeters are modulated. The id attribute is a text string containing the unique identifier of the light element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The type attribute indicates the basic type of light source. The default value is 'POINT'. Optional attribute. Materials describe the visual appearance of a geometric object. The material element categorizes the declaration of rendering appearance information. The material element contains declarations of shaders, parameters, techniques, and vertex and pixel programs. A material element is the base container for all rendering and shading information. The visual appearance of a geometric object is described by its material properties. The material element may contain zero or one asset elements. The material element may contain zero or more param elements. The material element must contain one or more shader elements. The id attribute is a text string containing the unique identifier of the material element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. A pass describes an algorithm that is executed during a single iteration of the rendering engine. The pass element declares the information required to execute a rendering pass. The param element may occur zero or more times. A param element specified as a child of the pass element is in the scope of only that pass. The input element may occur zero or more times. The input element must not have the idx attribute when it is the child of a pass element. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The program element may occur zero or one time. Shaders describe the process of rendering the appearance of a geometric object. The shader element declares the rendering techniques used to produce the appearance of a material. The shader element contains declarations of parameters and techniques. The param element may occur zero or more times. A param element specified as a child of the shader element is in the scope of all the shader's techniques. This implies that the parameter is invariant across all the techniques as well. Each technique element specified corresponds to a (platform) profile. This implies that the set of techniques are mutually exclusive. However, an application may choose to apply information from multiple techniques. The technique element must occur one or more times. The asset element may occur zero or one time. The param element may occur zero or more times. The pass element may occur zero or more times. The program element may occur zero or one time. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the technique. Required attribute. The id attribute is a text string containing the unique identifier of the shader element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. Textures embody the visual detail of the surface of a geometric object. The texture element embodies the sampling aspects of texturing. The asset element may occur zero or one time. The param element may occur zero or more times. The param elements describe the texture's dataflow with the associated material. The texture element may contain zero or more technique elements. The technique elements embody its functionality such as image lookup or procedural generation. The asset element may occur zero or one time. The param element may occur zero or more times. The input element may occur zero or more times. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The program element may occur zero or one time. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the technique. Required attribute. The id attribute is a text string containing the unique identifier of the texture element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The code element declares the executable code for a program element. The code element may contain a text string value. This string value is interpreted as source code. The id attribute is a text string containing the unique identifier of the code element. This value must be unique within the instance document. Optional attribute. The lang attribute indicates the programming language that the code is stored in. Required attribute. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the code. Optional attribute. The semantic attribute is the user-defined meaning of the code. Optional attribute. The url attribute is a valid URL to the location of the code resource. Optional attribute. The entry element declares an entry point into the executable code for a program element. The entry element may contain zero or more param elements. In the scope of the entry element, the param element must have the qualifier attribute. The value of the qualifier attribute depends on the technique profile in scope. Also the param element may not have the flow attribute. The id attribute is a text string containing the unique identifier of the param element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The semantic attribute is the user-defined meaning of the parameter. Optional attribute. The type attribute indicates the type of the value data. This text string must be understood by the application. Required attribute. The function attribute indicates the name of the entry point. Required attribute. The semantic attribute is the user-defined meaning of the code. Optional attribute. The program element declares parameters and program code that executes within the application runtime environment or the graphics pipeline. Programs use the same id/url linking (define/reference) facility as other elements. To define a program, specify an id attribute value. To refer to a program (i.e. a "function call"), reference that id value in a url attribute. Another way to refer to a program is by using a name as the URL value such as: <program url="PHONG"> In this case, the name refers to a well-known or built-in program. It's not a URI fragment (#PHONG) because it's not in the same instance document. It's implicitly defined in the COMMON profile. This element may contain an asset element. The param element may occur zero or more times. A param element, specified as a child of the program element, indicates the interface to the program. The value of such a parameter may vary each time the program executes. The code element may occur zero or one time. The id attribute is a text string containing the unique identifier of the program element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The url attribute is a valid URL to the location of the program resource. This resource contains information understood by the application run-time according to the technique profile in scope. Optional attribute. Cameras embody the eye point of the viewer looking into the scene. The camera element declares a view into the scene hierarchy or scene graph. The camera contains elements that describe the camera's optics and imager. The camera element contains one or more technique elements that describe its operating parameters for optics and imaging. The camera technique element must contain an optics element and zero or more imager elements. The optics and imager elements each contain a program element. For simple cameras, a generic technique need only contain an optics element that describes the field of view and viewing frustum using canonical parameters. The asset element may occur zero or one time. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the technique. Required attribute. The id attribute is a text string containing the unique identifier of the camera element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The instance element declares the instantiation of a node, an object or the contents of another COLLADA resource. The url attribute indicates the URL of the location of the object to instance. When the url attribute indicates a geometry element then the instantiation does not resolve any controller elements that may target the geometry element. When the url attribute indicates a controller element then the instantiation resolves the controller element and its target, such as a geometry element. Required attribute. The channel element declares an output channel of an animation. As an animation transforms value over time, those values are directed out to channels. The animation channels describe where to store the transformed values from the animation engine. The channels target the data structures that receive the animated values. The id attribute is a text string containing the unique identifier of the channel element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The source attribute indicates the location of the sampler using a URL expression. Required attribute. The target attribute indicates the location of the element bound to the output of the sampler. This text string is a path-name following a simple syntax described in Address Syntax section of the COLLADA specification. Required attribute. The sampler element declares an N-dimensional function. Animation function curves are represented by 1-D sampler elements in COLLADA. The sampler defines sampling points and how to interpolate between them. When used to compute values for an animation channel, the sampling points are the animation key-frames. Sampling points (key-frames) are input data sources to the sampler. Animation channels direct the output data values of the sampler to their targets. COLLADA recognizes the following interpolation types: LINEAR, BEZIER, CARDINAL, HERMITE, BSPLINE. The input element must appear one or more times. Sampling points are described by the input elements that refer to source elements. The semantic attribute of the input element can be one of: INPUT, INTERPOLATION, IN_TANGENT, OUT_TANGENT, and OUTPUT. The semantic attribute is the user-defined meaning of the input connection. Required attribute. The source attribute indicates the location of the data source. Required attribute. The id attribute is a text string containing the unique identifier of the sampler element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The skin element contains vertex and primitive information sufficient to describe blend-weight skinning. The skinning information is stored outside of the affected geometry, under the skin element. This decoupling allows skeletons to 'skin' multiple geometries and different instances of a geometry element to be modified by different skeletons. * Bind-shape: represented with a source, the same way as mesh vertex positions. * Influences / joints: a combiner represents the variable-length influence lists for each vertex. * Bind-pose: to avoid inverting matrices on import, COLLADA stores the inverse of the bind-matrices. The matrices are per-node (they are the same for each vertex that is influenced by a certain node). This is represented by two matching arrays (one for the nodes and one for the matrices) and combined by the joints element. Note that any node can be an influence, not only joints. The name of the joints element was chosen for familiarity reasons. There must be a one-to-one correspondence between the vertices in skin and the mesh vertices. Naturally, if a mesh is exported in its bind-shape (the skeleton was not moved after binding), the bindshape positions in the skin will be the same as the vertex positions under the targeted mesh. Also, the skeleton's transforms will result in matrices that, after inverting, will match the inverse-bind matrices in the skin. The source element must occur one or more times. The source elements provide the bulk of the skin's vertex data. The vertices element must occur exactly one time. The vertices element describes the skin vertices that are formed from the vertex data. The id attribute is a text string containing the unique identifier of the skin element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The asset element defines asset management information regarding its parent element. Computers store vast amounts of information. An asset is a set of information that is organized into a distinct collection and managed as a unit. A wide range of attributes describes assets so that the information can be maintained and understood by software tools and humans. The author element contains the name of an author of the parent element. The author element may appear zero or more times. The authoring_tool element contains the name of an application or tools used to create the parent element. The authoring_tool element may appear zero or one time. The created element contains the date and time that the parent element was created and represented in an ISO 8601 format. The created element may appear zero or one time. The modified element contains the date and time that the parent element was last modified and represented in an ISO 8601 format. The modified element may appear zero or one time. The revision element contains the revision information for the parent element. The revision element may appear zero or one time. The source_data element contains the URI to the source data from which the parent element was created. The source_data element may appear zero or one time. The copyright element contains the author's copyright information applicable to the parent element. The copyright element may appear zero or more times. The title element contains the title information for the parent element. The title element may appear zero or one time. The subject element contains a description of the topical subject of the parent element. The subject element may appear zero or one time. The keywords element contains a list of words used as search criteria for the parent element. The keywords element may appear zero or more times. The comments element contains descriptive information about the parent element. The comments element may appear zero or more times. The up_axis element contains descriptive information about coordinate system of the geometric data. All coordinates are right-handed by definition. This element specifies which axis is considered up. The up_axis element contains one of: X_UP, Y_UP, or Z_UP. The default is the Y-axis. The up_axis element may appear zero or one time. The unit element contains descriptive information about unit of measure. It has attributes for the name of the unit and the measurement with respect to the meter. The unit element may appear zero or one time. The default value for the name attribute is 'meter'. The default value for the meter attribute is '1.0'. The measurement with respect to the meter. The name of the unit. The extra element declares additional information regarding its parent element. An extensible schema requires a means for users to specify arbitrary information. This extra information can represent additional real data or semantic (meta) data to the application. COLLADA represents extra information as techniques containing an arbitrary number of param elements. The technique element may occur zero or more times. The extra element restricts the permissible child elements of the technique element to the asset and param elements. This element may contain an asset element. The param element may occur zero or more times. The profile attribute indicates the type of profile. This is a vendor defined character string that indicates the platform or capability target for the technique. Required attribute. The id attribute is a text string containing the unique identifier of the extra element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The type attribute indicates the type of the value data. This text string must be understood by the application. Optional attribute. -DEPRECATED- The boundingbox element declares an axially aligned bounding box that encompasses the geometric extent of a node in the scene graph. If the boundingbox is transformed by rotate elements then the resulting bounding box is an axial aligned box that encompasses the original bounding box. The min element contains three floating-point values for the minimum corner of the box. The sid attribute is a text string containing the sub-identifier of the min element. This value must be unique within the scope of the parent element. Optional attribute. The max element contains three floating-point values for the maximum corner of the box. The sid attribute is a text string containing the sub-identifier of the max element. This value must be unique within the scope of the parent element. Optional attribute. The sid attribute is a text string containing the sub-identifier of the boundingbox element. This value must be unique within the scope of the parent element. Optional attribute. Nodes embody the hierarchical relationship of elements in the scene. The node element declares a point of interest in the scene. A node denotes one point on a branch of the scene graph. The node element is essentially the root of a sub graph of the entire scene graph. The node element represents a context in which the child transform elements are composed in the order that they occur. All the other child elements are affected equally by the accumulated transform in the scope of the node element. The transform elements transform the coordinate system of the node element. Mathematically, this means that the transform elements are converted to matrices and post-multiplied in the order they are specified to compose the coordinate system. Allows the node to express a lookat transform Allows the node to express a matrix transform Allows the node to express a perspective transform Allows the node to express a rotational transform Allows the node to express a scale transform Allows the node to express a skew transform Allows the node to express a translational transform Allows the node to express a bounding box Allows the node to instantiate another copy of an object Allows the node to recursively define hierarchy Allows the node to define extra information The id attribute is a text string containing the unique identifier of the node element. This value must be unique within the instance document. Optional attribute. The name attribute is a text string containing the name of the node element. Optional attribute. The type attribute indicates the type of the node element. The default value is 'NODE'. Optional attribute. The scene embodies the entire set of information that can be visualized from the contents of a COLLADA resource. The scene element declares the base of the scene hierarchy or scene graph. The scene contains elements that comprise much of the visual and transformational information content as created by the authoring tools. The hierarchical structure of the scene is organized into a scene graph. A scene graph is a directed acyclic graph (DAG) or tree data structure that contains nodes of visual information and related data. The structure of the scene graph contributes to optimal processing and rendering of the data and is therefore widely used in the computer graphics domain. Allows the scene to express a lookat transform Allows the scene to express a matrix transform Allows the scene to express a perspective transform Allows the scene to express a rotational transform Allows the scene to express a scale transform Allows the scene to express a skew transform Allows the scene to express a translational transform Allows the scene to express a bounding box Allows the scene to recursively define hierarchy Allows the scene to define extra information The id attribute is a text string containing the unique identifier of the scene element. This value must be unique within the instance document. Optional attribute. The name attribute is a text string containing the name of the scene element. Optional attribute. The animation element categorizes the declaration of animation information. The animation contains elements that describe the animation's key-frame data and sampler functions. Animation describes the transformation of an object or value over time. A common use of animation is to give the illusion of motion. A common animation technique is called key-frame animation. A key-frame is a sampling of data at a known point in time. Using a set of key-frames and an interpolation algorithm, intermediate values are computed for times in between the key-frames, producing a smooth set of output values over the interval between the key-frames. A key-frame animation engine performs these computations on the key-frame data. An animation element contains the elements that describe animation data. The actual type and complexity of the data is left to the child elements to represent in detail. The animation element must contain one or more source elements. The animation element must contain one or more sampler elements. The animation element must contain one or more channel elements. The id attribute is a text string containing the unique identifier of the animation element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The controller element categorizes the declaration of generic control information. A controller is a device or mechanism that manages and directs the operations of another object. A controller element contains the elements that describe control data. The actual type and complexity of the data is left to the child elements to represent in detail. The skin element must occur exactly one time. The id attribute is a text string containing the unique identifier of the controller element. This value must be unique within the instance document. Optional attribute. The name attribute is the text string name of this element. Optional attribute. The target attribute indicates the ID of the geometry element bound to the controller. Required attribute. Geometry describes the visual shape and appearance of an object in the scene. The geometry element categorizes the declaration of geometric information. Geometry is a branch of mathematics that deals with the measurement, pr