Vray and wrong scene scale for dynamics

[sharktacos]

Other than SSS, are there other aspects of the Vray render which are affected by scene scale? I'm asking because Maya needs to do dynamics at a wrong scale (1cm = 1 meter, where the scene is set to cm, but a person would only be 150mm instead of 150cm).


We can compensate for this with the scale parameter on the SSS2 material, but I am wondering if other things will be affected as well, so we can take that into account as well. For example scale also affects light intensity and shadow softness on Vray lights.

[Morbid Angel]

Other than SSS, are there other aspects of the Vray render which are affected by scene scale? I'm asking because Maya needs to do dynamics at a wrong scale (1cm = 1 meter, where the scene is set to cm, but a person would only be 150mm instead of 150cm).


We can compensate for this with the scale parameter on the SSS2 material, but I am wondering if other things will be affected as well, so we can take that into account as well. For example scale also affects light intensity and shadow softness on Vray lights.

Scaling also affects displacement value so be aware of that.

[sharktacos]

Scaling also affects displacement value so be aware of that.

True. Also bump would be similarly affected.

I should clarify that I don't mean what the affect of changing the scale of scene would be, but rather whether there is anything (other than setting the SSS scale to 0.1) that one would need to account for if the scene scale was purposely set to a wrong value from the beginning (scene scale set to 1cm, but everything modeled as if 1cm = 1m).

I think the answer is no, but just wanted to confirm.

[joconnell]

Fog in the vray material too. We found for this stuff, especially when dealing with the likes of naiad caches that it's handiest to use exports where possible so you can bring in a cache of the object once it's dynamics are baked and then just scale it back up.

[sharktacos]

Another possible issue would be xGen for hair. If we are working with a scale of 1cm = 1m then that would mean the width and other attributes would need to be 10x smaller. I think that could go below the minimum number allowed for attributes (.001). That would speak for the need for lighting to be at a correct scale (1cm = 1cm), and scaling up the geo caches from dynamics.

The hairy issue here is cloth sims for characters. I would imagine what would best is to have the rig made at normal scale, but scale it down for the cloth dynamics (one would need to make sure the rig could scale correctly), then scale the resulting cloth dynamics cache back up for lighting. So long as the pivot point for the main scale was at the world center, that should work fine I think.