SI_Shape

Specifies a shape: vertex positions, normals, colors, and (for version 3.5 and beyond) texture coordinates.

For versions 3.5 and later, TEX_COORD_UV# indicates that the shape contains a set of UVs. TEX_COORD_UV0, … TEX_COORD_UVn extends the SI_Shape template. The name of the UV domain follows the TEX_COORD_UV ID.

There are two possible layouts for the information:

• Ordered—used to define an original shape

• Indexed—used to specify shape animation in SI_ShapeAnimation

Limitations

This template changed between version 3.0 and 3.5. Version 3.0 (and previous versions) does not support the texture UV coordinate information, but version 3.5 and beyond does.

 

For a mesh, the original shape definition is in the SI_Shape template named “SHP-<objectName>-ORG” that occurs outside of the SI_ShapeAnimation template. This is true only for meshes.

For a NURBS or patch surface, the original shape is defined by the SI_NurbsSurface or SI_PatchSurface.

Introduced

2.0

Template

// Ordered form used to define original shape 
SI_Shape SHP-<objectName>-ORG
{
   <nbShapeArrays>,
   <layout>,

   // Arrays for each element (vertex positions, 
   // normals, colors, texure UV coordinates) being 
   // described in the template. There are always at 
   // least two (one for positions and normals each)
   <nbElements>,
   <elements>,
   <value_array1>,
   ...
   <value_array[nbElements]>,

}
// Indexed form used in SI_ShapeAnimation to specify shape animation 

SI_Shape SHP-<objectName>-<shapeIndex>
{
   <nbShapeArrays>,
   <layout>,

   // Arrays for each element (vertex positions, 
   // normals, colors, texure UV coordinates) being 
   // described in the template. There are always at 
   // least two (one for positions and normals each)
   <nbElements>,
   <elements>,
   <index1><value_array1>,
   ...
   <index[nbElements]><value_array[nbElements]>,

}

Members

Member

Type

Description

nbShapeArrays

int

Number of arrays in the template. There is one array for every kind of information.

For example, a simple cube without any texture projections or color indices contains 2 arrays: one for POSITION (the array of vertex positions) and one for NORMALS (the index of normals).

layout

char *

Specifies how the information is laid out in the template. Possible values are:

• ORDERED = Defines an original shape.

• INDEXED = Specifies shape animation in SI_ShapeAnimation.

nbElements

int

Number of this kind of element in the array. For example, there is one array of position values for each vertex in the template.

elements

char *

Specifies what kind of information appears in this section. Possible values are:

• POSITION = Array of positions for vertices.

• NORMAL = Array of normals information (see ni below).

• COLOR = Template contains Color information (see ci below).

• TEX_COORD_UV# = Template contains texture UV coordinates information (see uvi below). The number sign (#) represents the number of the texture UV coordinates starting at 0.

Note: The TEX_COORD_UV# element is only available in v3.5 and beyond.

If more than one of these is present, use a vertical bar to separate the strings (for example, "NORMAL|COLOR|TEX_COORD_UV0|TEX_COORD_UV1").

Note: Vertex positions are always present in a SI_PolygonList template (see vi below).

material

char *

Name of the material.

Note: This is only available in v3.5 and beyond.

index

int

Index (zero-based) of an element (position, normal, color, or uv coordinate) in the corresponding array of the original shape.

Note: This is used for indexed forms in shape animation templates only .

value_arrayi

array of ints

The structure of the array depends on what element was specified for this block of data:

• For POSITION, value_arrayi takes the form: <posxi>,<posyi>,<poszi>.

• For NORMAL, value_arrayi takes the form: <xi>,<yi>,<zi>.

• For COLOR, value_arrayi takes the form: <ri>,<gi>,<bi>,<wi>.

• For TEX_COORD_UV#, value_arrayi takes the form: <ui>,<vi>.

Note: The TEX_COORD_UV# element is only available in v3.5 and beyond.

Example

SI_Mesh MSH-superlow_scene.sphere37
   SI_Shape SHP-superlow_scene.sphere37-ORG {
       3,
       "ORDERED",
       3,
       "POSITION",
       0.164448,-8.263903,-0.94169,
       0.905932,-7.565758,0.607855,
       1.435514,-5.374897,1.758833,

       3,
       "NORMAL",
       0.138088,-0.923712,0.357335,
       0.350603,-0.761782,0.544762,
       0.533405,-0.203967,0.8209,

       3,
       "TEX_COORD_UV1",
       <texture space 1 name>
       1.0,0.0,
       -0.0,0.0,
       1.0,0.1,
       ...

       3,
       "TEX_COORD_UVn",
       <texture space n name>
       1.0,0.0,
       -0.0,0.0,
       1.0,0.1,
   }

   SI_TriangleList
   {
       1,
       "NORMAL|TEX_COORD_UV0|...|TEX_COORD_UV2",
       "superlow_scene.mat88",
       0,1,2,
   }
}

Softimage|Crosswalk v3.11