More than 8 lights?

[j d.james]

Hi everyone -- first time post, but I've been lurking on the site for a little while.

I wanted to ask a question that got addressed on the Daz forum in about 2013, but I was wondering if anything had changed:

Are there any graphics cards that can handle more than 8 lights in a scene? The only reason I ask is because if there's a box stating it in Daz... then surely... it must be variable? Otherwise why bother having a section for it and not just put it in the manual that Daz can only handle 8 lights and leave it at that?

8zve1d.jpg (34.38 KiB) Viewed 9018 times

[uncannyvalet]

technology has likely advanced in the 11 years since you last investigated this issue, one can assume. I am not aware of any limitations on lights when rendering in iray, but perhaps there would be limitations if using legacy renderers and features such as 3delight, which some people are wont to do. Why, I do not know.

As for the "box stating it" and "manual" you are referencing, it remains unclear to me what these are.

You can always render on CPU instead of GPU if you run out of VRAM in Daz Studio Iray, so technically one would not need a high powered GPU to render any scene. An alternative of course is to use a Bridge (e.g., to Blender) and render a scene in another software to get around any limitations there might be with one's own hardware or Daz Studio itself.

[calie.vee]

Here's your answer, if you're talking 3dl lights, you can have more then 8 lights, however, in the preview only up to 8 can been seen, the render however will do more then 8, depending on the strength of your machine.
https://www.daz3d.com/forums/discussion ... a-daz-tech

[mgaen]

I'm pretty sure Iray can handle any number of lights. Iray is a path tracing renderer, which means the only way for it to turn your scene into pixels is to simulate the physical path of light rays between light sources and the camera. Perhaps counter intuitively, this simulation will converge faster if there are more light sources (because less dark corners).

For a simple rasterizer like the OpenGL preview (a.k.a. "the viewport" / "Texture Shaded" preview), it is different. It starts from the base color for each face and then "shades" it based on the angle between the face normal and the direction of light. It is very fast, and far less realistic, but I guess it adds up under real-time constraints if you have to support more lights sources.

So, like calie.vee, I think the limitation to 8 lights applies the OpenGL viewport only? It is pretty much outdated, and anyway its support for light preview is very bad. Most often, it just turns your scene black. Usually I disable it by unchecking "Preview Light" under the Window menu. Unfortunately you have to do it again each time the application starts.

For rendering with an older GPU, the limitation you will encounter will be the amount of VRAM more than other things. If your scene doesn't fit in GPU memory, it will switch to CPU rendering which is a lot slower.

PS: the Iray paper mentions tens of thousands of light sources. Note that emissive surfaces count as Iray light sources just like spotlights. https://raytracing-docs.nvidia.com/iray ... system.pdf (page 8)

[rustdragon4001]

So, like calie.vee, I think the limitation to 8 lights applies the OpenGL viewport only? It is pretty much outdated, and anyway its support for light preview is very bad. Most often, it just turns your scene black. Usually I disable it by unchecking "Preview Light" under the Window menu. Unfortunately you have to do it again each time the application starts.

The black screen issue with light preview can be easily fixed by toggling the preview with Ctrl+L.
I hope this helps you.

[mgaen]

Yes thanks! Much faster than going in the menu