Glass problem in Multi/Submaterial

[ruud3dv]

I thought the glasstrouble in multisub materials was fixed with 1.50 but i'm experiencing some weirdness still...

Glass in the model is made of 6mm solids in the 4 sides of the staircase.
To save time to show this, I only did a lightcache, so minor differences are not important.

If the glass is used in a multisubmat without wrapper, refraction seems to treat the 4 sides of the staircase as a solid glass block.

If it's used with a wrapper (all default settings: generate + receive GI 1,0 / caustics 1,0 / alpha constribution 1,0 / no matte surface refraction looks ok, but light isn't let through properly.

If it's used in a single material, no wrapper, the result is ok.

But since i'm using linked-dwg's with blocks i really need to use multisub materials.

Any thoughts on this? Is it a bug?

[vlado]

Let me try this here and see what I get.

Best regards,
Vlado

[vlado]

In my simple test here everything was fine; I tried to get a situation similar to yours, but the glass rendered fine inside a Multi/sub-object material.

If you wish, you can send me the problemmatic portion of the scene to vlado@chaosgroup.com and I'll check what may be wrong.

Best regards,
Vlado

[ruud3dv]

Thx, emailed part of the scene.

I've seen some more weird multi-sub behavior on dwg-linked geometry, like solids that didn't get the right material based on their autocad-color. So I suspect it's got something to do with the linking, and would make it an Autodesk problem... in which case I can only dream of the support like i'm getting from you guys

Linked dwg is from Autocad 2008, Max version 9 x64 ext.1 rev. 3, Vray 1.50.00

[vlado]

So if you disable the Opacity map in the material called "Alu perfo" it will render fine; you can get a similar effect if you use the map in the Refraction slot with IOR set to 1.0.

This is already corrected for future builds.

Best regards,
Vlado

[ruud3dv]

Thank you very much!

So i guess the opacity-map of one material 'polluted' other transparant submaterials?

Refraction-slot approach works ok indeed, with an inverted map in the reflect-slot. The beauty of opacity-map use is you don't need to mask the other effects, so i'll happily use that in the next build again

Thanks again, excellent support!

[re:FORM]

Sorry to hijack this thread, but I have a problem that I think is related.

Glass as its own material works fine....but the same material as the only material in a multi/sub material totaly changes the shading. The geometry mat ID is all 1, so its not a miss-assigned material.

Also, when using the multi-sub material, it renders considerably slower.

[vlado]

Which V-Ray version is that?

Best regards,
Vlado

[re:FORM]

Hi Vlado,
Its the latest public release, 1.5 RC3.

The reason I want a multisub material is to place displacement-mapped details over the bottle. If there´s another way to do this that avoids using a multi-sub map, I could try that.

One other quick question related to this model, when I have a planar mapped decal for putting an embossed logo on the bottle(using the displacement slot), the displacement appears on the back of the bottle also. If I use the same decal in the diffuse slot of a vray material, it does not project through to the back face of the bottle. Why does the displacement slot apply the map to both front and back of the bottle, and is this a bug or an expected behaviour from vray? (Since this is a different issue I could start another thread).

Thanks for your help

p.

[Dynedain]

In 1.5 RC3, the affect alpha and affect shadows checkboxes didn't work when the material was within a multi-sub mat. Switch to 1.5rc2 or 1.5 Final.

[vlado]

The glass problem with multi/sub materials is now solved in the final 1.5 release on site; for the planar-mapped logo, I would actually expect this to happen, but I'll have to do some more tests.

Best regards,
Vlado

[re:FORM]

Thanks.

hehe, I thought 1.5 RC3 WAS the final version... I must be out of touch!

I´ll download 1.5.00 and see if it helps.

In the end I´ve fixed the problem by applying the different displacements in a composite map with a different uvw for each. It works a treat.

I am noticing a very long ´geometry unloading´process when I cancel a render though.

Thanks again.

[re:FORM]

just a quick update. The problem has indeed been solved with the latest build of vray. Thanks vlado!

Can´t believe I missed the latest release!

[Da_elf]

i would unwrap the UVW for the bottle. i had to do something simular with the plastic spout in a carton of juice and the thread to screw the cap onto i displaced but the inside surface of the plastic piece was displaced with a thin groove only.... got the image here somewhere

i did this waaaay back.