Virtual Texturing: RuntimeVirtualTextureOutput Node Can Be Used with a Virtual Texture Domain Material

When adding a RuntimeVirtualTextureOutput node to a Virtual Texture domain material, the RVT Output node overwrites any data being sent to the normal material node's output, which interferes with the material's intended use. The RVT Output node should generate an error when it is placed in a Virtual Texture domain material indicating it is not compatible with that material domain. This doesn't seem like a desired workflow for the user to use and is likely to cause more confusion around the intended function of the RVT Output node.

1. Open RVT_Test from QAGame in the editor
2. Direct the camera to look at the magenta splat decals in the level
3. In the Content Browser, search for and open SplatDecal_RVT_Mat
4. In the material graph, right click and place a RuntimeVirtualTextureOutput node
5. Click Apply in the Material Editor toolbar

Expected Result
The RuntimeVirtualTextureOutput node doesn't affect the material since nothing is being passed to it, or an error is generated indicating the node can't be used with Virtual Texture domain material types.

Actual Result
The RuntimeVirtualTextureOutput node overwrites the data being passed to the normal material output node causing the decals to appear as magenta squares and no error is generated in the Material Editor