Here's a Thought

[treddie]

Why can't there be more than one Sun in Daylight mode? Is not the Sun in Octane, rather like a procedural? And does that explain why scenes lit with it render so fast? If this is true, then it seems that multiple Suns, or more generally multiple procedural emitters can be carefully placed in a scene without resorting to the slowdown caused by mesh emitters. If the coordinates are known for each procedural light, it seems render times would shorten dramatically. These procedural lights could also have primitive like shapes that correspond to typical lamp shapes.

Along those same lines, and when future GPU memory is large enough to do it, I do not see why emitters cannot be "baked" into a 3D HDRI. Bitmap images are for the time being 2D. But a 3D bitmap can store a stacked set of 2D planar bitmaps, where light sources have definite positions in a 3D scene. The theory is unquestionable. The execution would however drive the bitmap size up to really high values since bitmap size would be according to the cube of the edge size, not the square of the edge size. BUT...The 3D bitmap would not necessarily require it to have that high of a resolution, especially if the emitters do not show up in reflections or are seen directly.

[dionysiusmarquis]

http://www.hdrlightstudio.com/image_based_lighting.htm?

[treddie]

Thanks for that! That's totally cool.

Now all they need to do is make it so the HDRI is volumetric (3D), because it looks like they are still producing a lighting environment where all lights sources are out on the surface area of a big imaginary sphere that encloses the scene. But it seems like it would depend on a renderer like Octane to understand 3D HDRI.