I’d like to know if there is a way to control specular contribution of a light on a Groom asset in any way, or if there will be.
Steps to Reproduce
- Place any groom in an empty scene
- Place a light in the same scene, and find its specular contribution
- Set “Specular Scale” to 0
- The specular contribution is still there
Hi, thanks for reaching out about this. It looks like this is a bug; I reproduced the issue and brought it up with the team. I don’t have an estimated timeframe for a fix, but updates on the bug’s status will be shown on this issue tracker link (which might take a few days to be accessible publicly):
As a workaround in the meantime, you could try changing which lighting channels are used for the light/asset, so that the specific light doesn’t affect the groom. I hope that helps.
No it doesn’t, I specifically want the light (direct lighting) but not the specular. Or at least I’d like to have any control over the specular.
Understood! The team is aware of the issue and is looking into it (although I don’t have an estimate for when this might be addressed).
Another workaround option in the meantime, although I’m not sure if it’ll be sufficient for your specific use case: If the hair doesn’t need specular from anything else in that particular scenario, you could set the specular to 0 (as a constant, parameter, or MPC) in the hair material; alternatively, you could use a hair material that’s set to Fully Rough (checkbox). If you were relying on the light to affect the color of the hair asset, you could fake the light color (and direction) directly in the material as well.
Thank you for the ideas, but they are not applicable in a production.
Hair does need to interact with the rest of the scene, and we cannot compromise the render by altering the material.
Faking the light in the material could be a solution for one specific instance, but at this point we’d rather just change the lighting and make the specular contribution less prominent.