Vray dirt improved control

[LudvikKoutny]

Hi,

from other renderers i work with, i am used to use AO/Dirt maps for procedural material creation. While in the other renderers this approach works (Mental Ray and Corona) in V-ray i always have big problems achieving exact effect i need as VrayDirt does not allow for sufficient control over the effect.

When i create worn edges effect for example. I need to achieve over exaggerated effect of the dirt map, but V-ray does not allow me to go beyond distribution and falloff values of 0. (Mental Ray and Corona have "spread value" which is very intuitive and convenient way to control strength of AO effect).

Let me demonstrate:

I have a simple cube and desired radius of AO effect set to 100mm...

Vray result at distribution 0 and falloff 0, can not go any lower:



Result that was very easily achieved in Corona renderer:



And this is the kind of effect that i can achieve with sufficiently controllable AO/Dirt map (all the edge wearing and dirt in corners is done procedurally by AO maps and procedural textures)



I hope to see improved control in VrayDirt too


Edit: I think that practical scenario of implementation could be simply allowing the distribution parameter to go into negative values

[vlado]

You can pipe the VRayDirt texture through an Output map and use the curves to adjust the effect as you need - I could argue that it's a lot more intuitive...

Best regards,
Vlado

[vlado]

Here is an example.

Best regards,
Vlado

[LudvikKoutny]

There is a big problem though... i usually put my base texture into the unoccluded or occluded slot, and if i crush VrayDirt through an output node, i will crush also all nodes that are fed into it. So if i put for example wood texture into unoccluded slot, it becomes completely black.

I could in theory use output of Vray dirt node as a mask for Mix node, but that would make my already complex node networks even more complex... (an example: )



...and thus it would not be very intuitive as similar setup as one displayed above would need 18 nodes (6*dirt+6*output+6*mix) instead of 6. But although being a quite painful, it's still a functional workaround. Thanks

[Dave_Wortley]

You could use the VrayDirt as a Mix amount in a Mix material so you're not crunching your textures, that'd be the better way to do it.

[LudvikKoutny]

You could use the VrayDirt as a Mix amount in a Mix material so you're not crunching your textures, that'd be the better way to do it.

Hehe, yes, i actually wrote that in my second post already, right above the picture

[wxyz]

Can you expand on your methodology for the example shot?

Hi,

from other renderers i work with, i am used to use AO/Dirt maps for procedural material creation. While in the other renderers this approach works (Mental Ray and Corona) in V-ray i always have big problems achieving exact effect i need as VrayDirt does not allow for sufficient control over the effect.

When i create worn edges effect for example. I need to achieve over exaggerated effect of the dirt map, but V-ray does not allow me to go beyond distribution and falloff values of 0. (Mental Ray and Corona have "spread value" which is very intuitive and convenient way to control strength of AO effect).

Let me demonstrate:

I have a simple cube and desired radius of AO effect set to 100mm...

Vray result at distribution 0 and falloff 0, can not go any lower:

[ATTACH=CONFIG]13040[/ATTACH]

Result that was very easily achieved in Corona renderer:

[ATTACH=CONFIG]13041[/ATTACH]

And this is the kind of effect that i can achieve with sufficiently controllable AO/Dirt map (all the edge wearing and dirt in corners is done procedurally by AO maps and procedural textures)

[ATTACH=CONFIG]13042[/ATTACH]

I hope to see improved control in VrayDirt too


Edit: I think that practical scenario of implementation could be simply allowing the distribution parameter to go into negative values

[trixian]

I always figured the best way would be to have a curve to control it (like in the built-in one). All you would need is a range spinner.
Dropping the vrayDirt into an output map should in theory give you this control, but alas, it does not seem to.

[vlado]

Dropping the vrayDirt into an output map should in theory give you this control, but alas, it does not seem to.

Why not? It seems to work fairly well. A curve control inside VRayDirt itself will not do anything much different.

Best regards,
Vlado

[trixian]

Tbh, it has been a while since I tried, so my understanding of this is based on my recollection of my failed attempt at getting the vrayDirt map to behave as I wanted.
Regarding your comment, I didn't actually mean that it would be solved by having its own internal output curve controll (the same one as in vanilla max), just that the curve might not be adjusting the dirt "gradient" in the same way one expects, so there might be a slight incompatibility between what the map produces and what the "output-curves" expect.
I guess I'll have to try again to make sure