Explicit bounds extension

[progschj]

Rendering algorithms may need to make decisions based on object/scene bounds. For rasterization APIs near and far planes need to be selected. Shadow mapping requires setting up a shadow projection encompassing all shadow casters etc.

On the other hand scenes may contain large objects such as ground planes whose size does not necessarily correspond to the area of interest in the scene. In these situations it may be preferable to explicitly set the bounds instead of having them implicitly derived.

This extension would add a parameter "bounds" of type FLOAT32_BOX3 to at least the world object but potentially also to instance, group, geometry and spatial field.