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Problems with dubbel reflections

Posted: Thu May 07, 2009 12:30 pm
by Assistant
Hi

Im working on a privet project were im placing a object inside a bottle.

The problem i now have is that the bottle gives me dubbel reflections like the glas thiknes is not a solid. "se image below"
I have marked out a few

Now when i done test renders i get alot of noise on the object inside even at SL 20. So im thinking of rendering the botle for it self and the object insede for it self. The botle render will have the objet hidden from camera but want it to give away the reflections.
Can this be done in a god way?
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Re: Problems with dubbel reflections

Posted: Thu May 07, 2009 4:44 pm
by Bubbaloo
What are your material settings for your glass material? I would use the high grade glass wizard preset for this.

Re: Problems with dubbel reflections

Posted: Thu May 07, 2009 5:21 pm
by JorisMX
Perhaps the inner polys are pointing outwards instead of inwards as they should?

Re: Problems with dubbel reflections

Posted: Thu May 07, 2009 9:08 pm
by Cadhorn
I would check to see if the model is a closed solid. Don't know what 3d software you're using, but in Rhino if you've got even one open seam anywhere then it treats the object as a hollow shell and renders it that way.

Re: Problems with dubbel reflections

Posted: Thu May 07, 2009 10:48 pm
by -Adrian
Exactly. Another interesting thing i observed was that in Modo i could simply place inverted spheres into a larger sphere and have a visually correct bubble ball. In Maxwell, i had to copy/paste them to the same layer as the containment sphere or Maxwell would treat them wrongly, like in your image.

Re: Problems with dubbel reflections

Posted: Fri May 08, 2009 4:34 pm
by caryjames
I have seen the same thing in the real world where light reflects both off of the outside of my watch crystal as well as the inner surface. I think that you don't often see this in glass ware because the outer surface is bumped and a bit rough, maybe your material settings are too clean? Maybe this is what you are seeing?

Re: Problems with dubbel reflections

Posted: Fri May 08, 2009 4:54 pm
by Bubbaloo
Who are you to question reality? :mrgreen:

Sometimes I see caustics or weird reflections (in the real world) and I think, "if that was a render, I would be questioning it's correctness". :lol:
To really know if it's correct, you would have to set up a real world scenario and compare.

Re: Problems with dubbel reflections

Posted: Fri May 08, 2009 5:00 pm
by -Adrian
Yes, my glasses show internal self reflections for example, but the problem i see in his scene is that the glass body doesn't seem to distort the wooden stand in any way. I think Cadhorn's suggestion is likely; Maxwell doesn't treat the glass as a closed volume.

Re: Problems with dubbel reflections

Posted: Fri May 08, 2009 5:02 pm
by Assistant
Hi thanks for all your replys.
The reference i had was with thiner glas and when it gets thicker this dubbel reflection hapens.

When i modelled it it was not suposed to be that thick and got anoyed by it. It did not feel righ or seamd to be right. It is not often even in thick glas it hapends. it depends also alot on the camera angle to the glas.

I have set up a scene in the studio to do more reference shoots.

will also make shore that the object is closed.

Re: Problems with dubbel reflections

Posted: Sun May 10, 2009 3:56 pm
by KurtS
Cadhorn wrote:I would check to see if the model is a closed solid. Don't know what 3d software you're using, but in Rhino if you've got even one open seam anywhere then it treats the object as a hollow shell and renders it that way.
you can clearly see that this is the case here. The bottle is not rendered as a solid, thats why there is no refraction where you see through the bottle.


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