Use light cache for glossy rays - Animation

[Morne]

Hi all

The manual says:
Use light cache for glossy rays - if this option is on, the light cache will be used to compute lighting for glossy rays as well, in addition to normal GI rays. This can speed up rendering of scenes with glossy reflections quite a lot. When you use this option, it is recommended to also enable the Retrace threshold option, which will prevent the light cache from being visible in very glossy surfaces.

What the manual DOESNT say:
How does this affect things for animation? Since it is computed quicker with the option ON, then does it stand to reason that it is less accurate? In other words with this setting ON, does it increase chances of flicker?

[Dariusz Makowski (Dadal)]

It depends what animation is it. If its static or moving objects

In basics. If you set up ur LC to be rendered in 1st frame only and use camera path with lots of samples then LC is static and is being prerendered for entire animation - its all fine no GI flicker, no Reflection flicker.

However if you dont set up ur LC to be static then you can get flickering in your REFLECTION pass. Not GI- Gi as well if its low settings but you will get flickering in Refl pass.

With moving objects I never really tried it so I dont know : p

Retrace threshold - only prevents it in areas where geometry is touching each other. Like ambient oclusion mask. But it still uses LC interpolation for other areas and can cause flicker if its moving and low samples.

[Morne]

It's for animation with moving objects - lc calculated for EACH frame

[Dariusz Makowski (Dadal)]

Then you will get flickering from glossy and GI calculations depending on the quality of the GI settings. You may want to not use LC for glossy rays - it really depends if there is any speed gain from LC with glossy with high settings over just not using it...

You may want to try rendering statick background if you can with quick good settings and then rendering moving objects separately.

[Morne]

This is with universal settings