Autoresize and vray step size for maya fluids

[R_Cyph]

been fiddling with maya fluids and rendering in vray 2.0.

1) autoresize doesn't seem to be support with vray. the dynamic offset doesn't seem to work. Can somebody confirm this?

2) vray doesn't seem to automatically adjust step size to voxel size as scanline and mental ray do. If I use fluid grid thats 300 maya units(cm) I have to adjust the step size under vray fluid extra attributes
to 5.0-10.0 from .01. Can this be confirmed as well?

[ivaylo.ivanov]

Yep, the step is hard-coded to 0.1. I don't think the auto resize feature is implemented yet.
I will write these issue in the to-do list.

[R_Cyph]

Has the autoresize feature been implemented yet?

[vlado]

Yes, it should be working in the latest nightly/stable builds.

Best regards,
Vlado

[R_Cyph]

Our studio/renderfarm machines are currently using chaosgroup_vray-2.00_18083 for maya. does the latest build use the same licence? Is there anything required beyond simply downloading the latest build? This is urgent as Vray is the only renderer we currently have implemented for network rendering. Please advise as soon as you can.

[vlado]

It uses the same license, yes. Ideally installing a latest build should work.

Best regards,
Vlado

[R_Cyph]

Is there any real difference between the nightly builds and 2.20 for fluids? ( which is seems to resolve the problem )

[Morbid Angel]

we were able to render maya fluids successfully on the farm, though we had runup cache problems but they were unrelated to vray.

[R_Cyph]

we updated to 2.20 and the auto resize issue is gone now BUT we're having some new issues with Vray and maya fluids. Are any of the following fixed in the nightly builds?

1) the transparency slider in the fluid shader seems to be backwards ( white is making the fluid opaque , slide to black and becomes more tranparent) this is the opposite to how maya/mentalray handles the slider

2) the shader vray uses seems to handle light alot differently then mentalray. Vray's shaders seems to allow alot more light into the fluid even when density is quite high. Is there a way to scale the shader? some of our fluids are simmed at 0.1 or .01 scale for speed.

3) light select passes don't seem to work with fluids.

[vlado]

There are some further improvements in the nightly builds, yes. If you have any further issues, please email me directly to vlado@chaosgroup.com (if you have any sample scenes, they will be extremely helpful) and we'll sort them out.

Best regards,
Vlado

[R_Cyph]

quick question:

Using vray 2.20 I'm having trouble getting similar quality with vray compared to mentalray or maya software with comparable render times. Aside from step size and max steps in the vray extra attributes for the fluid is there any other settings that greatly affect rendering fluids with vray ( shading quality under fluid attributes seems to have no affect with vray )

[vlado]

The default volume shader that we use is VRayEnvironmentFog, which is a pure brute force volumetric shader. It does tend to be on the slow side as it does not perform caching of the lighting or anything like that.

Installing Phoenix FD will allow V-Ray for Maya to use the Phoenix FD shaders to render Maya fluids, which tends to be quite a bit faster. We might eventually end up bundling these shaders with V-Ray for Maya itself, but for the moment they are separate.

Best regards,
Vlado

[R_Cyph]

We currently don't have licences for pheonixFD for maya. Are you saying installing the demo would be fine for using just the shaders?

[R_Cyph]

I just checked the download section. I'm not sure I have access to the pheonix FD for maya demo either :P

[vlado]

Well, we can arrange that... can you email me to vlado@chaosgroup.com with your login name for the download section on our site?

Best regards,
Vlado