how can i fix these eyelashes shadows?

jstilton

hi,

i know that we can't avoid objects casting shadows in iray, but in the attached pic it seems that the top of the hair and the eyelashes are casting weird and unwelcome shadows. i don't seem to have it with other characters though. this is a g2f. What can i do?

thank you

mjc1016

That's not shadows...

Sometimes it's a problem with the transparency map.  Either it isn't a greyscale map or it isn't being correctly gamma corrected.  You can try adjusting the cutout opacity or the map (click the map as if you were going to change it and bring up Image editor and check it's correction settings...

Or sometimes, depending on the version of Studio, it's a bug with where the model is located.  Which version of Studio are you running?

jstilton

thanks. it's 4.9

so i have three people in this scene, two of them gen2F, one genesis. all three have it when i get close enough with the camera. they don't have it in a totally other scenes. so this should exclude some possibilities, i think?

jstilton

so apparently those shadows do or don't appear according to the scene (environment, lights, or whatever, but it's not just the character itself apparently)

 

 

sfaa69

I've never run into that particular problem, but my inclination would be to delete the lights first to make sure it's not the settings on one of them.

vwrangler

It may not actually be shadows. Check your character to make sure of two things: (1) the eyelashes shader is Iray Uber, and not omUberSurface -- there's sometimes an issue with that surface, and (2) your eyelashes have a map in the Cutout Opacity slider, and maybe in the Base Color slider as well. Sometimes that gets stripped out if you're changing from a 3Delight shader to Iray Uber.

orologiaio87

Hello... I have the very same problem with the eyelashes, exactly like in the image posted earlier.

I see a solution has been given already but the thing is I'm a newbie... I don't know the first thing about DAZ 3D. I'm not expecting a full guide on the programme but if someone could just tell me how to fix the eyelashed problem step by step, telling me excactly where the things are, I would be truly grateful.

Thanks

 

svArtist

For me, the issue was Max Path Length in the iRay render settings.

Of course you should make sure your eyelashes cutout opacity map uses an actual black for full transparency, but if when you end up here, I expect you've already checked that.
There used to be a bug linking this problem to the character's absolute position in the world coordinates (its distance from the 0,0,0 center) - but I would think that one has long been dealt with.
In my case, the character was pretty much in the center anyway.

Make sure your Max Path Length isn't too low (Setting it to auto (i.e. -1) is your safest bet to avoid ugly results).

I set a limit of three because I thought Path Length was about things like reflection depth (like mirror in mirror recursions, I remembered something like that way back in 3DS Max) - I didn't think it would affect transparency/shadows.

A limit of four gave me better eyelash shadows, but when I put the hair back on, there were still some issues in overlapping areas.

I finally set the value back to -1, the small performance boost wasn't worth always worrying whether or when another issue crops up, making me have to render the whole animation again path length changed the overall lighting feel for me, too. Guess it's about all photons)

 

This is a ray depth of 3:

This is a ray depth of 4: