What causes these marks?

Jayne Wilson

I did a render yesterday using Predatron's Boudoir Photo Studio set. I absolutely love the set, along with the outfit and poses for Genesis 2 Female (I used Olympia 6)

BUT - when I looked at my 3000 x 2400 render, there are bars of shadow or something on the skin of her arms, chest, face. The attached image is a small area of the render at full size so you can see what I mean.

Can someone tell me what's causing it, and how I can get around it?

My post DAZ solution was to use the smudge tool in PSE to get rid of the marks, but I would prefer it if they weren't there in the first place.

mjc1016

Which renderer? Skin shader? Render settings?

Jayne Wilson

The renderer is 3Delight. I used Olympia 6's skin materials. I tried with and without the SSS - same results.

I haven't delved into the render settings, other than changing the size of the rendered image, so it was just whatever is the default.

mjc1016

It's not quite the 'crocodile skin' so, it's probably not the SSS group ID problem, especially if it's doing it with SSS off...

So it's likely to be shadow bias (what type of shadows on the lights)?

Or, shading rate (try less than 1, something around 0.2 to 0.5 ).

Jayne Wilson

The lights have shadow maps - I selected that option over ray-tracing, which I know nothing about. The ray traced may have worked better.

There's a whole lot about the newer versions of DAZ I know nothing about. If someone could point me to an Idiot's Guide to Lighting, I'd appreciate it :-)

mjc1016

Shadowmaps used to be the faster option, but 3Delight has greatly increased the speed at which raytraced shadows are rendered and it's now the preferred option. So raytraced shadows are what you should be using. Shadowmapped shadows are done as a 'pre-pass' of just the main shadow casting geometry and that pass is saved and combined with the 'beauty pass' (final render pass). Raytraced shadows are made during the main render pass, using actual light/geometry interaction calculations.

And no, no basic tutorials, off the top of my head, for recent versions of Studio.

Ashcloud

The issue is related to the characters subsurface maps. Like mjc1016 said, switching to raytraced lights should solve the problem. If not, check the Subsurface Shading Rate for the character's materials. 32 or lower should work (the lower the value the higher the quality).

Jayne Wilson

Thank you very much for your help. I'll try the ray tracing.

Jayne Wilson

I'm doing a test render now, with raytraced shadows and it looks like the problem may be corrected. I'll be able to say for sure when it's done rendering.

Thanks for the info.