Bug (Case 1262413) Graphics.CopyTexture doesn't work to copy compressed Texture2D in Texture3D

Using Graphics.CopyTexture to copy the content of a Texture2D object in a Texture3D slice, does not work, if the Texture2D and Texture3D use a compressed texture format.

Reproduce

• Open attached project
• Select "New Texture3D Atlas" asset in Project window and lock its Inspector
• In the Inspector, enable the "Slice" button and set the X=256, Y=256 and Z=1.5
• Notice the Texture3D displays a blue gift texture and shows "256x256x3 RGBA 32 bit 0.8 MB"
• Open another Inspector window
• Select the "Bike", "Gift" and "House" textures and lock their Inspector
• Switch to the "PC Standalone" tab in the Inspector
• Choose "RGBA 64 bit" as format and press Apply
• Notice the Texture3D still displays correctly
• Choose "RGBA Compressed DXT5" as format and press Apply
• Notice the Texture3D displays garbage

Actual
Graphics.CopyTexture does not copy correct data in depth slices other than the first one, if the source texture is using a compressed format.

Expected
Graphics.CopyTexture should work for compressed textures and for all slices.

Note
In alpha 16 this related issue was fixed.

 

Link to issue tracker:
https://issuetracker.unity3d.com/is...to-texture3d-when-the-texture2d-is-compressed

 

This does not work with crunched textures.