I remember that some years ago, have produced a rendering in 10/15 hours was cause for pride. Now it simply means that you are a newbie!

Reducing the time in the rendering production is a goal to keep in mind. We need improve our skill reducing our rendering time too. Then go ahead! But how do? I wrote down some points that I hope can be a starting point for an analysis of your personal “rendering behavior“:

1) Use Low resolution for rendering tests.
I know, everyone likes to render a big image, but we risk to waste too many time if we always use 800×600 minimum.

2) Use Rendering Region: render only what interests you. Time to time check your shaders, verify the little differences.. and quickly find the result you’re looking for.

3) Do not add Glossy effects. Add it just when you think that the scene works fine. (I know that everyone loves Glossy effects, but we risk wasting much time.)

For V-ray users:

4) when we start the scene use fast parameters for GI:Primary buonces:
Irradiance map / -4 -4
Secondary bounces: Light Cache / 100

5) In the Vray Global Switches rollout use Override Mtl. We can use a very simple material like gray to test the light in the scene. When we are convinced of the light scene add the various shaders.

6) In DMC Sampler rollout, increse Adaptive amount from 0,85 to 1,0
The image quality will be lower, but also the time to render it!

7) About Vray Light, check the option “Store with irradiance map“. Even here, lose a little of shadows but the time is decidedly lower.

All this attentions will allow us to lower a lot the time setting. The final time rendering will be only a small part of a comparison!!

Have I forgotten something?
I hope it is a useful reminder and I hope to improve this post with your suggestions.
I await your comments and advice!