Question Tweaking shperical harmonics code for non-photorealistic lighting

Hello,

I have a project that uses stylized lighting that is non-photorealistic, and has features to adjust the colors of shadows including ambient occlusion contribution color. In illustration, artists often depict lighting and shadowing with shifts in hue that are not photo-realistic. However, Unity's global illumination system (URPs progressive one or Enlighten) calculated lightmaps in a photorealistic manner. I would like to adjust the code that controls how lightmaps are created if this is possible???

For example, lets say there is a red sphere in a room where each wall is a different color. On one wall, the ambient lighting on the wall picks up the red light bouncing off the red sphere and colors the wall slightly red where it is close to the ball. On another nearby wall, I would like the ambient lighting to appear more orange, even though currently the lightmap would add a red color, since the sphere is red. I want to tweak how lightmaps are created for specific objects. Perhaps at the point where radiosity is calculated, I want to choose the color that is bounced off the red sphere to a DIFFERENT color for a specific object's lightmap.

I believe lightmaps are already created per object. I am trying to find out how a specific object's lightmap might receive different color information based on user-controlled presets when the lightmaps are generated (i.e. one wall receives ORANGE light from red ball while another wall receives RED light from red ball). One person suggested tweaking the meta pass, but this would affect an object's CONTRIBUTION to global illumination, so in the above example it would change how the red ball contributes to GI thus changing how ALL the walls receive ambient lighting due to the red sphere. I want to change a specific object's RECEIVING color of ambient light, if that makes sense.

How do I found the source code that needs adjusting? Is this possible?

Thank you!

 

You can try modifying the lightmaps directly in photoshop or your favourite image editor. You can even do separate passes for each light, modify them one by one and then blend them together to have the whole lightmap.

Maybe this solution makes not sense for your specific problem or is something you cannot do.

 

Do you know I would replace the lightmaps in the engine with the ones I edited in photoshop?