Skin Rendering Green Randomly

GeneralDee

It doesn't happen on every render. But I'm getting an increasing number of green skin renders. This is trouble especially with animation. What is the usual suspect with this?

EDIT:
I have a feeling it has something to do with deep shadows on the lights. When I render an image sequence with no shadows, the render color issues don't happen but the scene does not look as good. I also notice when I use the deep shadows, I get little artifacts in some frames and have to clean up. So what's with the Shadow rendering in 3Delight?

Herald of Fire

Do you get the same issue using Raytraced shadows? Deep Shadow maps are an old way of handling shadows which is now superseded.

GeneralDee

HeraldOfFire said:

Do you get the same issue using Raytraced shadows? Deep Shadow maps are an old way of handling shadows which is now superseded.

Gonna try that next. I wanted to stick with deep shadows because Raytraced shadows have longer render times. But I will compromize considering the time it takes to go through and clean up sequence images. I will report results a little later.

GeneralDee

I tried the raytrace shadows method and find it to take substantially longer to render. The Raytrace shadow renders look very nice but I will be saving that for major animation projects if I don't figure a way to get the animations into a better render engine first. I was still getting artifacts too but no Hulk flashes. I think I may do better when I figure out a workflow to get my animations from DAZ to Blender and finally to Thea Render. This render engine just seems unstable and at times unpredictable and somewhat limited. It's good for still shots. Before I give up on 3Dlight, can anyone tell me what are the major parameters that affect render times and what are the usual causes of artifacts and faulty skin rendering? Perhaps I'm still missing something.

Herald of Fire

Too many variables to factor, but I can assure you that raytracing shouldn't be significantly slower than deep shadow maps if you're using the latest version. Though, this will also vary depending on the number of shadow samples. It will also vary depending on what lighting solution you're using. Things such as ambient occlusion can significantly slow render times if you're using a lot of opacity maps, such as hair.

Your render settings will also play a huge part in this. The lower your shading rate, for example, the more calculations it runs. A low shading rate of 0.1 gives a great appearance but also takes 10x longer to render than a shading rate of 1.0.

I find 3Delight is one of the faster engines available. If you're having slow renders with it, there are many reasons why this could be the case, some of which would only be highlighted further using alternate render engines causing even longer render times. What system specs are you using to render? Your hardware will obviously play another large role in how quickly you can render a scene.

Lastly, how busy is your scene; how many models are you using? Are you using HD morphs and so on? There's a laundry list of considerations to think about when working on a render. A 'typical' frame for me only takes 2 minutes to render, while some of my more intensive ones have taken over 8 hours.

GeneralDee

Thanks Addict. I started a new thread as my next thoughts go off topic of this one. My rig info can be found here http://www.daz3d.com/forums/discussion/51356/

Emmson2

Thanks for this thread... the green skin was about to drive me mad :)

I'm using Raytraced Shadows now to avoid the render failure. I must say that in my case raytracing works pretty much faster than Deep Shadow Mapping.

Another interesting fact is, that i created a series of photos with Deep Shadow Mapping and almost never received green renders. Now, in another scene (but with the same model) it doesn't work at all, skin is always green 0o

Anyway, Raytraced Shadows are the solution. 3D visualization is full of miracles :)