Geometry instanced to particles doesn't refract (VRay MTL)

[Brendon Morfitt]

like the title says. No refraction through the geometry instanced to particles on the VRayMTL. (VRay 1.5sp1)

[jbuttell]

Any word on this? I find that it doesn't matter if they're instanced or not. Vray/Maya particles appear to not work at all through refraction. Using 1.5.13942, maya2011.

I discovered it using basic and nparticles... but just built a simple scene consisting of an nParticle system (defaults) and a sphere (to confirm refraction works on regular geo) and a plane to refract through. Particles and sphere using vray lgt material. Only sphere renders through plane, although you can see particles outside the refractive plane....

[t.petrov]

jbuttell:
Is vray lgt material the same as VRayLightMtl?
If yes, do you have direct illumination enabled?
If direct illumination is disabled the particles render fine here (vray 2.15.00 rev16xxx).

I'll try 1.50sp1, too see what is happening there.

/Teodor

Edit:
1.50sp1 13989 works the same as 2.15.00.
Can you give as a scene?

[jbuttell]

Hi Teodor,

Yes, VRayLightMtl, sorry about that. If I enable direct-illumination, it doesn't render anything to RGBA, even without the refractive plane. This build seems very problematic in this respect.

In the case of refractive plane, same problem happens with VRayMtl, nothing renders through the refractive plane.

I can't provide a scene at the moment, but the steps to reproduce are as described. If that doesn't work, I'll see what I can do to get one to you.

thank for taking a look!

[jbuttell]

Tried in maya2012 using build 2.0.15968, same exact behavior. ;/

Created nparticle system, added vraylgtmtl, render and it shows up in RGBA. Enable direct light, nothing. Refractive plane, same issues.

[t.petrov]

It doesn't show because it has never been implemented.
Have you seen it work? In any build?

[vlado]

The "direct illumination" option in the VRayLightMtl material works only on simple triangle meshes for the moment. This is because, internally, the V-Ray for Maya translator exports a mesh V-Ray light rather than the actual geometric object. However our Instancer plugin does not work for lights currently.

Best regards,
Vlado

[jbuttell]

The "direct illumination" option in the VRayLightMtl material works only on simple triangle meshes for the moment. This is because, internally, the V-Ray for Maya translator exports a mesh V-Ray light rather than the actual geometric object. However our Instancer plugin does not work for lights currently.

Best regards,
Vlado

Thanks, direct-light not working makes sense. Teodor, no I haven't ever seen that work, I was just reporting my findings. However, the problem persists with particles not refracting even without the direct-light option enabled. Vraymtl also behaves the same - that's my main concern. I need particles to refract through. Any idea why this doesn't appear to work?

[vlado]

Any idea why this doesn't appear to work?

It would be best if you can get us a scene; otherwise it's hard to figure out what's going on.

Best regards,
Vlado

[jbuttell]

Will post one shortly, thanks Vlado.

[jbuttell]

Should have looked here immediately, thought I did, but it turns out the vis flags default to off. They're even locked in that state.

[vlado]

Heh ok; that was an easy one

Best regards,
Vlado