How to speed up rendering of transparent objects

martinkeitel_e65f08430a

Hi.
3Delight engine produces excellent results when it works. It's extremely slow to render scens with objects that have some transparency. This comes evident with most hair objects, but even more so if you use large transparent objects.

I am just rendering a scene of the witch house and I've added a very simple to make fog object: Just put several vertical plane primitives on top of each other and use a transparency map that fades towards the top and has some noise. Is there any way to speed up the rendering of transparent objects (like meddling with the advanced render settings)?

JonnyRay

Unfortunately, this has been an issue with Renderman based engines for a long time. Pixar keeps working on optimizing it, but for us DAZ Studio users, we're kind of at the mercy of 3Delight doing their updates, then DAZ updating DS with a new version as well. You can help yourself a little bit by keeping things like your "Ray Depth" rendering settings at a level where you get the look you want, but not so extreme that it is hurting your render times.

Another idea for fog like effects would be to do it in post-processing. You could do something like a depth rendering pass that does a simple grayscale shading based on how far away the object is from the camera. Then in post processing, you use that as a mask to control how much of the fog effect applies to each part of the image.

Chohole

If it's any consolation Poser Firefly renderer and both the Bryce renderers also slow down when dealing with transparencies.

Richard Haseltine

The witch house uses a lot of standard point lights, and has a lot of transparency mapped leaves on the trees. That means 3delight is spending a lot of time calculating shadows on lights that are too dim to see. You can get a big speed up if you replace all of the point lights with linear point lights (copy the settings from a point light with ctrl-c, delete it, add a linear point light from the create menu, ctrl-v to apply the settings, then set a reasonable distance end value such as 300 or so) so that you aren't getting a lot of time wasted on lights that will have no visible effect.

martinkeitel_e65f08430a

JonnyRay said:

Unfortunately, this has been an issue with Renderman based engines for a long time. Pixar keeps working on optimizing it, but for us DAZ Studio users, we're kind of at the mercy of 3Delight doing their updates, then DAZ updating DS with a new version as well. You can help yourself a little bit by keeping things like your "Ray Depth" rendering settings at a level where you get the look you want, but not so extreme that it is hurting your render times.

Another idea for fog like effects would be to do it in post-processing. You could do something like a depth rendering pass that does a simple grayscale shading based on how far away the object is from the camera. Then in post processing, you use that as a mask to control how much of the fog effect applies to each part of the image.

Is it possible to make a z-buffer map in Daz studio? I mean to get it to the whole scene at once?

JonnyRay

mkeitel said:

Is it possible to make a z-buffer map in Daz studio? I mean to get it to the whole scene at once?

Yes.

1. Select the camera you want to use (or create a new one if you don't want to lose your current settings)
2. Open the Shader Builder
3. Expand the Volume tree and find RI_DepthCue
4. Apply that to your selected camera
5. Render

mjc1016

Volumetric fog should be faster, at least a little, than stacked transparencies...

martinkeitel_e65f08430a

Thanks, I will try that :)

scorpio

Have you tried applying uber surface shader and turning off occlusion and raytracing.