Important

Changing the bound shader program used for rendering is an expensive operation, which is why this information is set at a high level in the render tree. Applications should aim for the absolute minimum number of changes to the shader program, so you should attempt to group all your content which shares the same shader program under the one render pass in the same IProgramNode node, and rely on child IStateGroupNode objects to divide content further if needed.

Important

It is strongly recommended to minimize the number of separate shaders your application uses. Shader programs can be very large and involve many conditional tests, and still be much more efficient than using sets of separate smaller shaders and having to change programs multiple times during the rendering process. For this reason, your application should aim to use large shader programs which provide state values to enable different kinds of operations as needed, such as texturing, stippling, lighting, or shading effects.