## 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