Reducing render time for Dome light

[banana28]

Although I really like the result of Vray Dome light, it takes so long to render. It needs quite high subdiv(around 64) if I need noise-less results.
I'm trying to stay simple without HDRI, and still, render time is (in my opinion) long.

Are there any tricks for Dome light to achieve a noise-less result in short render time?
Or should I just stay in low subdiv during test renders.

[joconnell]

For your test renders the best thing you can do is use the colour threshold in the anti aliaser section. It's 0.01 by default which is often good enough for final production, for test renders I'll set that at 0.1 or 0.05 - it'll mean vray works to much lower standards and you've only got one control to change.

[LudvikKoutny]

DomeLight itself in V-Ray is quite fast, but if you need to get crazy with subdivs and get long rendertimes, then I think your sampling setup may be messed up. It's really quite difficult to understand, and even more difficult to make that understanding work in practice. So I would suggest to skip the step of getting into it and wait for new V-Ray 3.3, which handles subdivs automatically by default. It still requires a bit of skill to be able to estimate how much ray branching should you use in different types of scene, but in general, entire performance control comes down to three global parameters - noise threshold, max AA subdivs and min. shading rate.

[banana28]

Thank you for the reply!
I tried changing the color threshold, and it seems good for test rendering.
It is nice to know the way others do. Thank you!

And yes..., Vray have too many settings, I need to spend so much time for different scene and lighting.
Me, too, looking forward for coming Vray 3.3.