When working with Chaos Corona and the Physical Material, there are often questions about the correct Gamma settings to use for different types of maps. This blog post aims to clarify these settings and provide guidance on how to handle them effectively.

1. Should the Gamma Always Be Left on Automatic or Should Override (1.0) Be Selected?

When loading bitmaps into different slots, the gamma setting plays a crucial role:

• Automatic Gamma: Use this for ordinary bitmaps, such as those loaded into the “Diffuse” slot. These maps are typically saved with gamma (sRGB) information, so the automatic setting will correctly apply gamma correction.
• Override (1.0) Gamma: Use this setting for grayscale textures like bump, displacement, and normal maps. These maps do not usually have gamma baked in and should remain linear; therefore, overriding the gamma to 1.0 ensures no unintended corrections are applied.

For other grayscale textures, such as roughness or height maps, you can select the gamma setting based on the specific results you are looking to achieve.

2. What Gamma Setting Should I Use for Different Maps with the Physical Material?

Here’s a simple guide:

• Base Layer/Diffuse Maps: Use Gamma: Automatic.
• Bump, Displacement, and Normal Maps: Use Override (1.0).
• Other Grayscale Maps (e.g., Roughness): Choose based on the desired outcome:
  • If the map is saved with gamma, use Automatic.
  • If the map is saved without gamma, use Override (1.0).

3. What About AO Maps (Ambient Occlusion Maps)?

AO maps are typically grayscale images saved without gamma correction. Therefore, when loading AO maps, generally use Gamma Override (1.0). However, if you are loading them into a “Corona Mix” or “Composite” and then into the “Diffuse” channel, this setting can vary:

• Automatic is often suitable if you are unsure of how the AO map was originally saved. However, experimenting with both settings (Automatic and Override 1.0) may be necessary to achieve the desired look.

4. What Is the Purpose of the Additional Bump Node in Corona Normal Map?

The Additional Bump Mapping slot in the Corona Normal Map allows you to combine an additional bump map with an existing normal map. This feature can be helpful if you want to mix multiple normal maps to create more complex surface details.

The Corona Bump Converter is another tool that can be used to apply adjustments to your bump map. It enables the use of 3ds Max’s native output settings, which can provide more flexibility in achieving the desired results.

Conclusion

Understanding how to correctly set the gamma values for various maps in Chaos Corona can greatly impact the final render quality. Always remember:

• Use Automatic Gamma for Diffuse Maps.
• Use Gamma Override (1.0) for Bump, Displacement, and Normal Maps.
• Select the Gamma Setting for Other Grayscale Maps Based on the Desired Result.

By following these guidelines, you can ensure your materials render correctly and achieve the visual effects you are aiming for.

The post What Gamma Settings should you use when loading textures in Chaos Corona? first appeared on CG Viz Studio | 3D Rendering Company.