What Decides Render Speed

jacob24068

What are the dependents for the time a render takes? Is Iray shader optimization a thing?

If I render just a single room in my own house model, it takes 3 minutes for 300 iterations, and the total triangles are around 115k.

If I render a character that is straight from the Daz, it renders 350 iterations in 3 minutes despite the model being 1.2m triangles

So obviously, triangles don't matter. The house wasn't using all textures made for Iray, however, some were. I am wondering if this could have anything to do with render speed?

Paintbox

They are a ton of threads on this, with more tips I can provide, but mostly the amount of bounces a ray makes determines speed. If rays can escape, render is fast. Like a character without anything around it is fast. As soon as you go indoor, the amount of bounces go up exponentially. 

So more lights, more surfaces where light can‘T escape, adds to the mix of lengthy renders. Now add transparent surfaces, like hair or glass, add reflections , means even more time.

Lastly the amount and the quality of your light. Mesh lights with a lot of surfaces like a sphere with a lot of triangles will lengthen render times.

Triangles and textures are of lesser concern, as long as you the have the vram to keep it on your card. That said I do believe the more free vram your card has, the better it is to speed up iterations.

I highly recommend 

https://www.daz3d.com/iray-ghost-light-kit

For soft window light mostly and

https://www.daz3d.com/scene-optimizer

For optimizing materials and scene objects. They can help in getting render times down. I would first learn to optimize without these tools however, especially if you’re new to DAZ or rendering in general. You’ll get the most out of them that way.