A single procedural virtual texture tile generation request, to be filled in CPU memory.
| height | Height of the requested rectangle. | 
| level | Miplevel of the requested rectangle. | 
| numLayers | Number of layers inside the request. | 
| width | Width of the requested rectangle. | 
| x | X offset of the requested rectangle. | 
| y | Y offset of the requested rectangle. | 
| GetLayer | Get the request properties of one of the requested layers. |