Need help caustics in Daz Studio

Zone 822

I'm trying to use caustics in Daz Studio 4.7.0.12. I followed these tutorials:

https://youtu.be/FwCHxSTlOQo
https://youtu.be/G2lwC6HHTrU

See image. The sphere has the shader mixer glass material that comes with DS. The sphere has a green diffuse color. The intensity of the caustic light is exaggerated to make the effects more visible. A shader mixer distant light made as in the videos is the only light. Camera is as in the videos.

I have these problems so far:

1. No reflections of walls or floor. I've tried different settings on everything can find about reflection. No luck.

2. Caustic reflected light is green like sphere's diffuse color. This is good.

3. Caustic transmission does not have sphere's green diffuse color.

4. Caustic light passes through objects with default shader.

5. Is this caustic reflected or transmitted light? It is not green like the diffuse color of sphere.

Any suggestions?

I found that Uber Environment bounce light does work with this caustic set up. Light is bounced as expected.

Richard Haseltine

Try setting the Opacity colour to magneta - diffuse colour doesn't affect the light passing through an object, even with regular shaders. I'm not sure what you mean by 4., I see shadows from the blocks.

Zone 822

Thanks Richard.

That's disappointing. The light passing through or reflecting from a transparent colored object should take on the color of the object as the default behavior. At least it can be adjusted for each object/surface so red wine in a clear glass, bunch of different color marbles, etc. can be done. I'm not impressed with the lack of access to some of 3Delight's important abilities or the lack of documentation on the shader mixer bricks. But I'm an occasional Daz user so no big problem. (Former trueSpace user who will move to Blender.)

About 4. Here is another render with the caustic light in red to make it more visible. I mean the light that has interacted with the sphere. You can see the red color in the corner of the two low walls. That should not be there. The shadows from the more direct light seem correct.

Any ideas about the missing reflections?

My goal is having caustics from light that went through slightly translucent glass. If these experiments work then I'll do a realistic still life including glass items.

Richard Haseltine

Hmm, I'm not sure what is happening there then - perhaps make a bug report (Technical Support ticket http://www.daz3d.com/help/help-contact-us ).

No, I'm not sure on reflections - they can be a bit tricky to set up in Shader Mixer as I recall.

Zone 822

Thanks again Richard. I'll use Kerkythea for rendering on this project. Modeling with Hexagon!

mjc1016

Richard Haseltine said:

Hmm, I'm not sure what is happening there then - perhaps make a bug report (Technical Support ticket http://www.daz3d.com/help/help-contact-us ).

No, I'm not sure on reflections - they can be a bit tricky to set up in Shader Mixer as I recall.

I've found that ShaderMixer reflections are one of the hardest things to get right...and it seems caustics is nearly as flaky. I tried for hours last night and couldn't get the refractive caustics to work properly...reflective (chrome), worked perfectly.

One of the possible causes for the caustic light 'leaking' through the blocks, is mesh density. If each face of the block is only one poly, then there's a good chance that's the reason. When I finally did get some caustics going, higher density meshes blocked them, while low density ones looked similar to what was posted.

Also, I had to go to 6 or 8 raytrace bounces to get noticeable surface reflections on the sphere I was using as a test object.

sriesch

Are there any premade light/camera/material combo products available, before I jump into pausing the video repeatedly, writing down each step and trying to reproduce this from scratch?