GPU - how to use the Max Trace Depth of materials?

[Micha]

Hi,

if the GPU mode is enable than the global Max Trace Depth can't be disabled anymore. How can the user switch to the Max Trace Depth of the materials?

-Micha

[konstantin_chaos]

Hi,

There is a difference in how the trace depth limit works on CPU and GPU.

CPU:
- Keeping the trace depth disabled lets you specify the value in every material separately
- Enabling the trace depth will override the material values, forcing the global trace depth for all of them
CPU Example:
If a material has trace depth lower than the global limit and the global limit is enabled - the global value is used.
If a material has trace depth higher than the global limit and the global limit is enabled - the global value is used.

GPU:
- The trace depth can't be disabled
- Setting the trace depth will not override the depth of individual materials - it's works as a global max.
GPU Example:
If a material has trace depth lower than the global limit - the material value is used.
If the material depth is higher - the global is used.

As a conclusion:
When rendering on the GPU it's safe to keep the global limit high as long as you take care of the material values.

Regards,
Konstantin

[Micha]

Very interesting. Thank you for the quick answer.

Could be good if this info could be added to the help page.