Annoying white outlines after rendering

tekkoontan

hi everyone, i need help on how to remove these annoying white lines that appears everytime i render something that has hair on it... the white line seems like it is trying to separate something from the dark shadows behind it.... how do i remove this? it makes my sculpting sucks.

look forward for your reply! thanks!!!

dpadam450

Do the hair strands have an alpha channel texture? If so turn of blending and just use alpha testing.

tekkoontan

thanks man, but i dont know where to check the alpha channel, have tried looking, but to no avail.

dpadam450

However the hair system works, it is probably using a texture that has alpha. The first strand is drawn which the edge is .5 hair + .5 white skin. When another purple hair strand renders UNDER that one, the previous blended hair has already been written to the screen and determined to be closer, so the hair underneath is disregarded.

Look at this picture though, it appears single strands still have the issue, which leads me to believe it is a texture sampling issue. Some programs (not sure which ones) will save an alpha channel as all white or all black etc. The GPU samples multiple texels for 1 single pixel and interpolates those colors. Here it seems that your alpha pixels might be white and when it does this sampling, it gives part white with 0% alpha + part purple with 100% alpha = 50% purple with 50% alpha.

tekkoontan

dpadam450 wrote: »

However the hair system works, it is probably using a texture that has alpha. The first strand is drawn which the edge is .5 hair + .5 white skin. When another purple hair strand renders UNDER that one, the previous blended hair has already been written to the screen and determined to be closer, so the hair underneath is disregarded.

Look at this picture though, it appears single strands still have the issue, which leads me to believe it is a texture sampling issue. Some programs (not sure which ones) will save an alpha channel as all white or all black etc. The GPU samples multiple texels for 1 single pixel and interpolates those colors. Here it seems that your alpha pixels might be white and when it does this sampling, it gives part white with 0% alpha + part purple with 100% alpha = 50% purple with 50% alpha.

i actually just started 3D so i dont quite understand it haha, but thanks alot. so what do i need to do to remove the white outlines?

Mark Dygert

What kind of material is applied to the hair?
Does it have an opacity map?

If so, it looks like the dead space is bleeding into the live area of the mask. You probably need to increase the edge padding around your hair image.

tekkoontan

i use the Skin material for the hair, not sure what is Opacity Map, but i will find out. it's definitely not the edge padding, because i dont use textures or UVs.

thanks btw!

tekkoontan

bump

Eric Chadwick

Which software is this?

tekkoontan

it's ZBrush Eric

Eric Chadwick

This is FiberMesh, right? See the Texture Selector section here
http://docs.pixologic.com/user-guide/3d-modeling/fibermesh/advanced-options/