public class MeshInstancingNode<T> : MeshNode, 
	IMeshInstancingNode
where T : struct, new(), IVertexType

Public Class MeshInstancingNode(Of T As {Structure, New, IVertexType})
	Inherits MeshNode
	Implements IMeshInstancingNode

generic<typename T>
where T : value class, gcnew(), IVertexType
public ref class MeshInstancingNode : public MeshNode, 
	IMeshInstancingNode

type MeshInstancingNode<'T when 'T : struct, new() and IVertexType> =  
    class
        inherit MeshNode
        interface IMeshInstancingNode
    end

Type Parameters

T

The vertex type which stores instance data, usually InstanceData.

This mesh node has a property Instances which defines a collection of instance data. The element type is a vertex structure. Each element in the collection encodes data for one instance of the mesh, such as world matrix, color and alpha.

Vertex structure:A suitable vertex structure to use for the instance data is InstanceData. InstanceData is supported by the standard material effects. However, custom vertex types can be used to store different instance data. If the vertex type is not InstanceData then the mesh must use custom material effects, i.e. custom HLSL shaders that know how to interpret the encoded instance data.

If an element in Instances is changed at runtime, InvalidateInstances must be called to inform the mesh node that any internally cached data must be updated.

Bounding shape: The Shape must be set manually to a suitable shape which contains all instances of the mesh! Per default, the shape is Infinite which is safe for rendering but those not allow culling and therefore is very inefficient.

Scales, poses and world transforms: When a mesh instance is rendered, a material effect can combine the scale and pose of the scene node with the transform stored in the instance data. The effect can also ignore the scale/pose of this mesh node and only use the transform in the instance data. Currently, the predefined material effects of DigitalRune Graphics use the later method because the shader is faster. That means, the instance data should store the world space matrix, and the scale/pose of the mesh node is ignored. (However, the scale/pose of the mesh is still used to position the bounding box for frustum culling!)

Limitations: Following MeshNode features are currently not supported and will be ignored when an MeshInstancingNodeT is rendered:

• mesh skinning (see also SkeletonPose)
• morphing (see also MorphWeights)
• occluders (see also Occluder)

Cloning: When an MeshInstancingNodeT is cloned the Instances collection is only copied by references (shallow copy). The original and the cloned mesh node will reference the same Instances collection.

Reference