What Causes These Black Lines in Eyes?

nabob21

Hello,

I have been getting some weird black lines by the lacrimals when I render a character based off of the Brandi character by Jessaii. Does anyone have any idea what could be causing them?

Thanks in advance for any help.

nabob21

abiflash

I think we both have that problem. 

https://www.daz3d.com/forums/discussion/371046/eyes-issues#latest

FenixPhoenix

Solution posted here: https://www.daz3d.com/forums/discussion/comment/5015501/#Comment_5015501

Short version: in render settings toggling from speed to memory or viceversa seems to clear the issue.

nabob21

Thanks FenixPhoenix. That seemed to fix the issue.

hansolocambo

Some artists don't respect a basic bleading/padding rule : texture (pixels) inside UV islands (unwrapped mesh) should always bleed enough outside of UV islands. Suggested amounts of edge padding are (depending on the texture's dimension in pixels, 4096x4096, etc.) :

• 256 = 2px
• 512 = 4px
• 1024 = 8px
• 2048 = 16px
• 4096 = 32px

In other words, if the vendor provides a 4096 pixels texture for the eyes but did a padding too small (in some vendors' products I've seen textures with no padding at all... ), then you'll get those black lines visible. The black is actually the texture's background color. If it was red, the lines would be red.

One way of fixing that is to open the eyes' texture in Photoshop. And paint around UV Islands a color similar to the one at the edge of the UV Island (using the stamp tool it's an easy task). Save that texture slightly modified, Ctrl+I in DAZ to refresh all textures : problem solved.

Most 3D painting solutions nowadays do the padding properly (Substance Painter, Quixel, etc) or at least propose an option to choose the bleeding size in pixels, from 1 to infinite.

NorthOf45

Sometimes it is actually that the sclera geometry crosses over the cornea geometry (caused by an eye morph), creating a hard line where there should not be any. Any number of surface settings can accentuate it.

hansolocambo

NorthOf45 said:

Sometimes it is actually that the sclera geometry crosses over the cornea geometry (caused by an eye morph), creating a hard line where there should not be any. Any number of surface settings can accentuate it.

I just noticed that and came back to modify my post before I noticed yours. I'm facing the same issue today and it's definitely due to some of my ZBrush strokes that changed a bit the eyes geometry.

EyeMoisture (same mesh as cornea) should always be completely around the Sclera (same mesh as Iris / Pupils). If a wrong morph makes the sclera to go through the Eyemoisture then those lines appear. A lot of morphs coming with girls bundles called "Raised Cornea" do just that and cause the issue. Because the vendor (Emrys), instead of making a bulge of only the cornea's area (which has its own Surface / Material ID to make it easily selectable), also modified the eyemoisture mesh making the sclera pass through.

Morality, when making custom morphs, it's important to freeze/mask the eyes to avoid distorting them even a little. And move/reshape them if necessary but as a whole mesh or really carefully.

3Diva

FenixPhoenix said:

Solution posted here: https://www.daz3d.com/forums/discussion/comment/5015501/#Comment_5015501

Short version: in render settings toggling from speed to memory or viceversa seems to clear the issue.

Thank you so much! I use an older version of Daz Studio for some of my NPR work and was having this same weird eye lines issue. The switching from Memory to Speed under "Optimization" fixed the issue for me. I was about to tear my hair out so thank goodness I found your comment! I know this is an old post, but I just wanted to say Thank You! You don't know how much of a help this is to me!