How to let Scene Bump affect AO in one rendering?

[flat]

How to let Scene Bump affect AO (extratex with VRayDirt) in one rendering? (beauty + AO)

[vlado]

Hmm, good question. I don't think there is a way to do it right now - perhaps we would need to add a bump slot to VRayDirt; or alternatively, a bump texture that can be used to apply the bump before calculating other textures. Which one do you prefer?

Best regards,
Vlado

[ashishdani]

This would be very helpful

@Vlado - with option 2, would this be a new texture node which we apply into the bump slot of our shaders ? BitmapTexture > "NewNode" > BumpSlot ? So would it work for a standard render as well (same as bumps look right now) as well as an AO render (either a render layer override or an ExtraTex) ?

I usually assign (AO) render-layer override with vRayDirt into a Light material as a material override , so in the case of option 1, if I have many materials assigned to various geo objects - would I have to assign a VRayDirt with the (related) bump map (into its shader) to every geo object ?

[flat]

simply,　wish the affect bump option for ExtraTex elements.

[freedomfries]

Is it feasible to just displace instead of bumping?

[freedomfries]

Hmm, good question. I don't think there is a way to do it right now - perhaps we would need to add a bump slot to VRayDirt; or alternatively, a bump texture that can be used to apply the bump before calculating other textures. Which one do you prefer?

Best regards,
Vlado

I'm no programmer, but would there be a way to grab the bump normals buffer and use it in the AO computation? Mental Ray seems to be working in that way. So this way, whenever a VrayDirt node is used, could there be a checkbox in it to consider texture normals? It would pull the data based on a particular render layer, so that the bump you would expect to see assigned is being considered? Rather than have to re-create a bunch of bump assignments, it would thus look at what is already in place. I hope it makes sense.

And would that slow down the render much?