scanline tab in mental ray renderer?

[RevitGary]

I noticed in the Renderer tab , Rendering Algorithms , there is a Scanline option. What does this do when you are using mental ray as the default renderer?

[WAcky]

directly copied from the help file:

 

Scanline group

 

Enable When on, the renderer can use scanline rendering. When off, the renderer uses the ray-tracing method only. Scanline rendering is faster than ray tracing, but cannot generate reflections, refractions, shadows, depth of field, or indirect lighting. Default=on

[RevitGary]

I am still confused. How could it be using scanline when I have mental ray set up as the default?

[WAcky]

Rendering Algorithms Rollout (mental ray Renderer)The controls in this rollout let you choose whether to render using ray-tracing, scanline rendering, or both. You can also choose the method used to accelerate ray-tracing.

 

 

If I were you I would do some testing with reflective materials. Try enabling the scanline option, render, turn it off, render compare renders and render times. Its obviously a quality control which will affect times and quality. If you look at the help file info -> "Scanline rendering is faster than ray tracing, but cannot generate reflections, refractions, shadows, depth of field, or indirect lighting" It probably means that when the scanline renderer detects that none of these effects are present then it will become the active renderer to save render time.

 

 

If you were to check the scanline option and uncheck the ray-tracer option then you would lose reflections, refractions, shadows, depth of field and indirect lighting.

 

 

It may be worth rendering a complete production still with and without this option to really see if and where it affects the image and how much, if any time you save.

 

 

But I could be totally wrong...

[RevitGary]

So if Scanline is not checked Mental ray only uses Ray trace? I would think this would make for slower rendering times?

 

Thanks for your videos Brian I got them all