This message occurs when Corona detects that some of the CoronaNormal maps contain map with gamma set up incorrectly.
Normal Map - correct result:
Normal Map - incorrect result due to wrong gamma correction:
- This can be easily automated for all materials in the scene using the Converter Script
- Alternatively, you can perform a quick fix by enabling “Add gamma to input” checkbox in CoronaNormal map containing offending input
- When loading bitmap file through the “Select Bitmap Image File” window, at the bottom part of the window, in Gamma section, click "override", and set its value to 1.0