PolygonMesh.CurrentVertexColor

Introduced

v3.0

Description

Sets or returns the current vertex color property (ClusterProperty) used by the polygon mesh's material. When you first create a polygonmesh it inherits a material but doesn't automatically have a vertex color. You need to explicitly set the vertex color to be used by the material (this then becomes the current vertex color proprety). The current color at vertices property may not be set, in which case the first vertex color property found will be returned. If the polygon mesh has no vertex color properties then Nothing is returned. Test to see if your variable equals Nothing to check if the cluster property is valid.

C# Syntax

// get accessor

ClusterProperty rtn = PolygonMesh.CurrentVertexColor;

// set accessor

PolygonMesh.CurrentVertexColor = ClusterProperty;

Examples

JScript Example

NewScene( null, false );

CreatePrim("Sphere", "MeshSurface", null, null);

// get selected elements from scene

if ( Selection.count == 0 ) {

	 LogMessage( "Nothing selected", siError );

} else {	

	 var objs = Selection;

	// get selected meshes from selection list

	var meshes = SIFilter( objs, "polygon_mesh", true, siQuickSearch );

	if ( !meshes ) {

		LogMessage( "No polygon meshes selected", siError );

	}

	// process selected models

	freezeNormalColors( meshes );

}

function freezeNormalColors( objs )

{

	// process all meshes

	for ( var i = 0; i < objs.count; i++ )

	{

		// get current mesh (type : "polyMsh")

		var obj = objs( i );

		// get obj material

		var mat = obj.Material;

		// if material is not local add one

		if ( mat.IsA(siSharedPSet) ) {

			mat = obj.AddMaterial();

		}		

		// get polygon mesh geometry

		var polymesh = obj.ActivePrimitive.Geometry;

		// get current vertex color property

		var vc = polymesh.CurrentVertexColor;

		// current vertex color property not set yet

		if ( vc == null ) {

			// no vertex color properties installed, add one. 

			vc = polymesh.AddVertexColor();

			// set the vc to be used by the polgon obj's 

			// material.

			polymesh.CurrentVertexColor = vc;

		}

		// set vertex colours from shading normal vectors

		// the parent of the vertex color is

		// a cluster. This maintains the relationship

		// between the actual node index and the corresponding

		// cluster index.

		var vcClsElems = vc.parent.elements;

		var nodes2 = new VBArray( vc.Elements.Array ); 

		var nodes = nodes2.toArray();

		var clsElemIndex = 0;

		// visit all polygons

		for ( var j = 0; j < polymesh.Polygons.Count; j++ ) {

			// get pointer on polygon

			poly = polymesh.Polygons( j );

			// visit all polynodes

			var polynodes = poly.Nodes

			for ( var k = 0; k < polynodes.Count; k++ ) {

				var node = polynodes( k );

				// get polynode normal

				var normal = node.normal;

				// lookup node index for vertex color

				clsElemIndex = vcClsElems.FindIndex( node.Index ) * 4;

				// compute corresponding color channels

				nodes[ clsElemIndex ]	 = ( normal.x + 1.0 ) * 0.5;

				nodes[ clsElemIndex + 1 ] = ( normal.y + 1.0 ) * 0.5;

				nodes[ clsElemIndex + 2 ] = ( normal.z + 1.0 ) * 0.5;

				nodes[ clsElemIndex + 3 ] = 1.0;

			}

		}

		// put the new colors back into the vertex colour 

		vc.Elements.Array = nodes;

	}

	return;

}

See Also

Material.CurrentUV PolygonMesh.AddVertexColor PolygonMesh.VertexColors