Direct light

[Percy_xue]

What is the purpose of Direct light section that is build in Object properties(on vray System panel)? I just can't understand all such as shadow, affect alpha, color and brightness. Can anyone kindly tell me about them? Much appreciate for that.

percy

[J_Bug]

Notice that the Direct light section you mentioned is contained within Matte properties section.

When rendering for composting you sometimes want the direct light to affect matte objects which are objects that don't get fully shaded but just parts of the rendering is considered. For instance if you want to animate a crazy alien walking through a video plate of your backyard and there is a large stone it steps over in the process. You could model the stone in 3D but only tell VRay to render the aliens shadow bending across the stone as the alien passes over it.

Shadow will turn on the shadow cast by Direct light

Affect alpha will give you the shadows alpha instead of the objects

The Color swatch and Brightness parameter works similar to the Color swatch and Dens. in a point lights Shadow Parameters rollout. These two color swatches work in conjunction by what I think is a subtractive process.

--Jon

[Percy_xue]

Thanks so much, Jon. Very good explaination.

Regards,
percy