V-ray RT question

[radiosity1980]

I have tried using vray rt as production render, so i can use the elements
-the render don't start, why?
-there are differences in the render elemente of vray adv and RT?
-In the RT setting the are some parameter, what are the settings to get a clean image?
-the cpu engine and gpu engine there have different settings , why?
thanks
sorry for my poor language

[Svetlozar Draganov]

Would you please first let us know what version/service pack of V-Ray/3DSMax/OS you are using.

-the render don't start, why?

Would you please create a new scene with a few basic primitives and a light and run another test about this issue.
Let us know if it works or not.

-there are differences in the render elemente of vray adv and RT?

Most of the elements will be identical but not all of them.

-In the RT setting the are some parameter, what are the settings to get a clean image?

The image quality when using V-Ray RT is controlled by 3-parameters.

Max Render Time - lower values means lower quality and vice versa.
Max Paths Per Pixel - lower values means lower quality and vice versa.
Man. Noise - lower value means higher quality.

The Shading Quality depends on:
Trace Depth and GI Depth parameters - higher values means better quality.

-the cpu engine and gpu engine there have different settings , why?

The difference is only in the performance/optimization settings. This is necessary because GPU devices are still very limited by the memory and they are much faster than the CPU.