Use VrayDirt in a whole scene?

[jophus14]

I have never used the VrayDirt mapping option and I want to try it out on a scene that I am working on. I have done some reading on the parameters and settings and what they do. My question is, do I have to make each material a VrayDirt material first, then apply my bitmap to that particulare VrayDirt shader and then proceed to do this with all of my bitmaps in the material editor "or" is there a way to apply VrayDirt to an entire scene all at once? Thanks for your help

[AJLynn]

Usually I would want the dirt as a separate pass for Photoshopping. Try the material override.

[jophus14]

How do you incorporate the final colored image and the image with VrayDirt applied? Doesn't the scene get really washed out due to the final image having many materials and the dirt image with a single texture and dirt in various places? Please explain how you render out a dirt pass and then combine the two in post production. Thanks.

[AJLynn]

The dirt pass is just white with darkening in places - it's an AO pass. Put it over the original in Multiply mode, then you can adjust the transparency or do curves on the layer or apply a layer mask or whatever.

[Ricardo Eloy]

I'm not sure what you want here, but you can check the detail enhancement option (IrrMap). It uses an AO pass (more accurate, though) and enhances the edges and junctions. Maybe that's what you need.

[jophus14]

Thank guys.

 

AJLynn: I will try to try your method of combining the layer in PS. I wasn't thinking of switching the layer type when incorporating the two layers. Thanks for the help.

 

Rick Eloy: The detail enhancement is something that I will have to try out as well. I will probably just do a small region since I heard that having the detail enhancement ticked caused the render times to go up quite a bit. I will compare the two (VrayDirt-AO layer with the detail enhanced render) and see which one looks better. If the detail enhanced method looks nicer then I will render out the whole scene using it.

[AJLynn]

The detail enhance method will be more "correct", the AO method would just darken surfaces that have other surfaces close to them - it's a kludge that often yields a correct-looking result and sometimes just makes your inside corners too dark.

 

BTW, I'm pretty sure detail enhance doesn't do AO in Vray (like that option in the mental ray A&D shaders does) - it addds some extra QMC calculation in the areas where Vray thinks IrrCache isn't going to do a good job.