OTOY Forums

hi all, would anyone know why i am getting this black distortion using hair props on G3 / G2 models?

I pulled the mesh into Zbrush and everything looks fine I also rendered in DAZ iRAy and its fine too, any thoughts?

https://www.dropbox.com/s/ih0qz2b3z5ewxyq/hair.jpg?dl=0

Two possibilities...

Ray Epsilon... not likely, that tends to be low on the forehead.

And Displacement... Octane doesn't play nice with intersecting displacements with other surfaces. Play around with scalp displacement values. Also check what is going on with your skin, as changing either can cause this. I prefer to use displacements for hair, and it gives another method for controlling intersections. You can simply adjust the offset for the hair to zero or even positive values.

Thanks, I assume you mean the Disp settings in the Octane MAT tab? I see most of the hair parts have Disp set to 1 Power, I am not sure if he offset value you mean = Power? Or is this a DAZ setting?

I set all Disp to 0 still no change in that scalp, the scalp itself has no disp map for it

thanks for the help

i did set Disp to 0 % in DAZ adn rebuilt scene seems better, is this what i should be doing for hair?

The problem you have is neither related to displacement, nor to ray epsilon values.

The hair mesh is intersecting with the head mesh of the character.
Adjusting the rayepsilon value can help with this (although it will only remove the visual intersecting areas shown in your pictures in black) but doesn't fix the actual problem.

Simply increase the hair figure / prob size slightly (say for example to 100,200 % - play with that value a little bit but try to always stay in the 100 %, just add decimal figures)

That should fix your problem

bpzen wrote:i did set Disp to 0 % in DAZ adn rebuilt scene seems better, is this what i should be doing for hair?

Play with your Strength, and Offset. A strength of .1 is 1mm displacement which should be plenty for displacement. An offset of 0 or even +.1 should clear most of that up.

first thing I try when I see that is turn off displacement. that fixes it most of the time.

if you want displacement then scaling the hair to be a tad bigger will work. However if displacement is the issue, you will still potentially see black spots in the hair elsewhere, which will be ugly.