New To VRay RT - Silly questions

[Infrared digital]

Just wondering but, I get better results when using the CPU engine rather than Open CL or CUDA, is this normal ? Sometimes I get different lighting results, could this be the result of the gamma settings somehow ?

Also, does VRay RT stop or can it be stopped ? I know that I can set a time limit.

How much do the settings in the production version of VRay affect VRay RT ?

How can I render an animation with RT?

Thanks

N

[Alan Iglesias]

I'll give these shot - hopefully others will chime in...

Just wondering but, I get better results when using the CPU engine rather than Open
CL or CUDA, is this normal ? Sometimes I get different lighting results, could this be the result of the gamma settings somehow?

When you say "better", how so exactly? Is it that RT/GPU is not yet supporting all the things you may be doing in your scene? If so, these things will most likely be supported eventually.

As far as lighting differences, yes, there are a few things that can make difference and it can differ scene to scene. Do a search based on lighting differences in RT/GPU, RT/CPU, and the standard Vray production renderer and I think you will find some interesting threads.

A good way to figure out what is going on with your scene is to start with a fresh scene, and do quick test-renders with both CPU and GPU as you go about lighting it and setting parameters. When you have done something that causes a difference, you will see it immediately.

Also, does VRay RT stop or can it be stopped ? I know that I can set a time limit.

Two primary ways. One is the time limit as you mention. The other is perhaps more useful as you set a limit to the number of rays per pixel that have been rendered (Render Setup/Active Shade/V-Ray RT/Rendering/Max paths per pixel). That way your noise and image quality will stay consistent render to render.

I also sometimes do it simply by hitting the clone button in the Active Shade window which will preserve the current rendering at it's rays-per-pixel state at the time of clicking.

How much do the settings in the production version of VRay affect VRay RT ?

It depends on which setting we are talking about. If you are referring to bias controls, such as IM and LC, they have no affect as RT always renders using progressive path tracing and will always strive to find a complete ray casting solution without limitations. Image sampling also is not set as PPT is always working progressively to reduce noise. Other controls, like those in Color Mapping and gamma settings are active in RT. This is not a complete list, so I hope others might mention some things I missed, but these are the most important to me.

How can I render an animation with RT?

Sure. You can make a quick preview using RT using the Rendering/Make V-Ray RT Animation Preview menu command. For more finalized work, simply set up your scene to use RT as the production renderer and fire away.

Hope this helps some,

-Alan

[Infrared digital]

Hi Alan

Thanks for your help with my questions, I will go through your answers later when I have some time.

N

[Alan Iglesias]

Most welcome!

-Alan