Problems with baking a hair cap
Hi
I seem to having some issues when baking a hair cap using Marmoset Toolbag 4. I've been following this tutorial - https://www.youtube.com/watch?v=_IU4DkEWTwI&ab_channel=iiCreative - but no matter how much I adjust the cage, I keep getting weird splotches on the low poly, or hairs that aren't even in those regions. I've set the cage to 0 just to show them more clearly...
But increasing the cage doesn't appear to help...
This is how the Normal map is looking...
And this is how the UV currently looks...
Maya's distortion checker does show some distortion, so could this be responsible...?
I kinda just stuck the first unwrap it generated from the mesh. I did do a test bake in Substance Painter, but the results are awful, no matter the settings I adjust. I also tried doing the baking in Maya, but that's preventing me from baking anything. :-\
Any suggestions? Thanks.
Replies
I've just tried modifying the UV and made some cuts, which has cleaned up the distortion, but sadly, the same issue happens when baking the hair. :( I'm totally out of ideas why it keeps doing this. The only shot in the dark I have now, and I feel it's highly unlikely to be the cause, is that the cap was extracted from a 3D Scan Store head mesh. Well, I used my own low poly head and then used the Wrap4D software to project/wrap it to a 3D Scan Store head mesh. Again, I don't see why that would cause a weird baking issue like this though.
Hey! Maybe it's hairs from the other side projected onto the faces. Is there is something like a max Ray distance? Else you could test it by having just hair geo just on one side, see if the issue persists.
Thanks for replying. As far as I know, there’s no hair on the opposite side…? I could be wrong though. The low poly hair cap is certainly only one sided, but would that stop an interactive groom in XGen from generating them through/on the other side?
Hm, not sure I understand. I meant the hair growing out on the opposite side of the head/cap. The splotches seem to appear on the sides, not on top?
Oh, I see. Yeah, the splotches are mainly around the sides. Are you suggesting the hairs at the sides are baking through to the other side? I'm not sure why they would if they're meant to be baking to the nearest surface. In this case, the low poly cap.
This is what the high poly hair looks like on its own:
And the roots are all facing inwards...
And they're sitting on the low poly cap...
Yes, that's what I'm suggesting :)
I'd say the rays cast from the cage inwards and wherever they don't hit the highpoly geo on the same side (hairs), they continue to the other side (unless ray distance is limited).
Currently can't test this myself. As I wrote, for testing one could bake with hair just on one side, to check if splotches persist.
Edit: Even easier: bake with highpoly hair-cap.
Can rays be adjusted in Marmoset Toolbag 4? And with a cage? I'm not 100% familiar with Marmoset just yet, so I'm sure there are customisable options I've yet to try. I've been able to adjust the offset of the cage so far.
I don't know. But I suggest baking with highpoly hair-cap included, to check if this solves it.
Okay, it looks like you're right. I've done three tests. The first, I removed all the hair from the sides and back and just had it on top. That baked out correctly. Then I had one where it was just the sides/back - that had the same issue...
And then I had the top and just one side/back. One side baked correctly, the other has bleeding...
Sorry, I missed this comment. Do you mean I should include the same hair cap with the high poly?
EDIT: Can't believe I didn't think of that. Such a simple solution. Thank you. :D
You could include the hair cap like mentioned or make the hair cap a shell just for baking. You can remove the thickness later. Intent is jsut to block the rays from crossing sides.
It's not possible to adjust the ray distance for the baker in Toolbag, it will search until it hits something. For cases like this, it's a good idea to include a blocker mesh in the high poly. This can usually be a copy of the low poly shrunk down a little so it doesn't intersect with the hair strands