New Vray Glass Bug Workarround

User avatar
Prodigy
Site Admin
Posts: 909
Joined: 21 May 2009, 14:46
Type the number ten into the box: 0
Location: Uruguay

New Vray Glass Bug Workarround

Post by Prodigy » 29 May 2009, 21:18

Ok guys! finally yesterday i found another workaround for the glass~GI bug.. :bananamouse:

This is more simple than the other i found.. just go to your vray panel, inside your GI settings change your primary GI set Lightmap to Irradiance. Secondry Gi also to Lightmap.. *you can leave the second bounce to direct cos the second bounce has less intensity than the first bounce.

I know is another kind of gi calculation but at least if you need to render glass in a realistic way you can try to use this method...

Cheers! :)

:bananacheers:
testet.jpg
๑۩۞۩๑ prodigy ๑۩۞۩๑

User avatar
Johny
Petty Officer First Class
Posts: 53
Joined: 21 May 2009, 17:14

Re: New Vray Glass Bug Workarround

Post by Johny » 30 May 2009, 14:59

Thanks for the hint Prodigy! :bananacheers:

How about try to make tS Vray render glass as shown on this link http://blender.bevice.ru/forum/viewtopic.php?f=10&t=209" onclick="window.open(this.href);return false;

You can donwload scene file on Blend format and then import it to tS via OBJ format. :worship:
Image

User avatar
spacekdet
Captain
Posts: 1624
Joined: 27 May 2009, 15:00
Type the number ten into the box: 10
Location: On the day shift at the Utility Muffin Research Kitchen
Contact:

Re: New Vray Glass Bug Workarround

Post by spacekdet » 30 May 2009, 15:05

I don't get it.
The one you have marked 'bug' looks better than the one marked 'no bug'.

Who wants black foam on their beer? bleech!

Sure they aren't mixed up?

User avatar
Prodigy
Site Admin
Posts: 909
Joined: 21 May 2009, 14:46
Type the number ten into the box: 0
Location: Uruguay

Re: New Vray Glass Bug Workarround

Post by Prodigy » 30 May 2009, 15:42

If you ask about the Right foam compared with the left one, yes im agree that looks better.

But you know what? that is a bug. The foam on the right is white cos the glass emit light and makes the foam brighten.

Here is another problem. Ts Vray has no option to exclude objects from the GI calculation. So for Vray, the Glass is equal to a Solid Rock that blocks the gi light.. That's why the left foam is dark. cos there's no light that make the foam brighten and cos i use glass you can see through the material..

There's just 1 solution for this..

Make the Glass invisible, Save the Gi calculation, make visible again the glass and load the GI calculation.
Tricky but is the ONLY way to solve this riddle..

Sad, cos i request exclude Gi calc since 7.11

Another good example of this problem is.
Add a Skydome over your Vray scene. ?You will see how there's no GI.. Cos is blocked by the skydome object..
๑۩۞۩๑ prodigy ๑۩۞۩๑

User avatar
Johny
Petty Officer First Class
Posts: 53
Joined: 21 May 2009, 17:14

Re: New Vray Glass Bug Workarround

Post by Johny » 30 May 2009, 18:59

Thanks for the hint again Prodigy! :)

Here is my render testing

(irradiance no caustics ; 1st bounce = 0.5)
Image


(irradiance plus caustics ; 1st bounce = 0.5)
Image


(lightmap no caustics ; 1st bounce = 1.0)
Image

(lightmap plus caustics ; 1st bounce = 1.0)
Image

test scene can download on below link (required tS7.6 with Vray)
http://rapidshare.com/files/238982530/glass.zip.html" onclick="window.open(this.href);return false;

Thanks!
Image

User avatar
spacekdet
Captain
Posts: 1624
Joined: 27 May 2009, 15:00
Type the number ten into the box: 10
Location: On the day shift at the Utility Muffin Research Kitchen
Contact:

Re: New Vray Glass Bug Workarround

Post by spacekdet » 31 May 2009, 05:21

Prodigy wrote:Add a Skydome over your Vray scene. ?You will see how there's no GI.. Cos is blocked by the skydome object..
Hmm, you sure about that?
... just running some tests tonight...
I get GI if I turn off shadowcasting on the dome object.
It couldn't be that simple, could it?
Attachments
gi_under_dome.jpg

User avatar
Prodigy
Site Admin
Posts: 909
Joined: 21 May 2009, 14:46
Type the number ten into the box: 0
Location: Uruguay

Re: New Vray Glass Bug Workarround

Post by Prodigy » 01 Jun 2009, 05:03

Yes, but that's because you increased the size of a sphere and then you can see only that the internal faces that are flipped..

That's why the light pass.. but try to do that flipping all the faces, or subtracting one sphere on other..

Do that also with a glass shader..

mmm i have an idea.. :lol:
๑۩۞۩๑ prodigy ๑۩۞۩๑

User avatar
spacekdet
Captain
Posts: 1624
Joined: 27 May 2009, 15:00
Type the number ten into the box: 10
Location: On the day shift at the Utility Muffin Research Kitchen
Contact:

Re: New Vray Glass Bug Workarround

Post by spacekdet » 01 Jun 2009, 14:19

Sorry to continue in an off-topic direction...but as far as i know, I didn't do any face-flipping at all.
I ticked 'backside' so that the inside faces would also render.
Wouldn't that in effect make it double-sided?
Not that it would matter if the outside of the dome rendered since you'd never see it anyway.

Hope your idea works out.

User avatar
Prodigy
Site Admin
Posts: 909
Joined: 21 May 2009, 14:46
Type the number ten into the box: 0
Location: Uruguay

Re: New Vray Glass Bug Workarround

Post by Prodigy » 02 Jun 2009, 15:48

Imagine you made a small sphere.. the faces are looking to its normal right? ok if you watch from the interior of that sphere, the faces still pointing to its normal instead to you that are in the "center" of the sphere.. i mean, from your point of view the faces are flipped..

If you flip the faces to the interior? the GI doesn't pass through the sphere..

So that was interesting cos i never tried that before :) so there's a solution for skydomes hehehehe

Knowing that, i thought this.. if gi pass through inverted faces, what about invert the faces of a glass material? in theory should work..

I still need todo some tests..
๑۩۞۩๑ prodigy ๑۩۞۩๑

User avatar
spacekdet
Captain
Posts: 1624
Joined: 27 May 2009, 15:00
Type the number ten into the box: 10
Location: On the day shift at the Utility Muffin Research Kitchen
Contact:

Re: New Vray Glass Bug Workarround

Post by spacekdet » 02 Jun 2009, 18:09

I turned on backfaces so that in effect it's now two sided... if I'm inside or outside it doesnt matter, I can still see the rendered sphere.
I think what's allowing the GI to pass thru the sphere is that I've turned off 'cast shadows' for the sphere.

Which wouldn't really work for glass, since you would want it to cast shadows.

Post Reply