[Axe]

Very impressive Thomas! Thanks so much for doing all the work! I'm more impressed with Maxwell all the time.

[Thomas An.]

air>
glass(in)>
glass(out)>
water(in)>
water(out)>
glass(in)>
glass(out)>
air

Adam,

We have already discussed about this hypothesis and the answer is no.
http://www.maxwellrender.com/forum/view ... sc&start=0

[tom]

Yes, I remember that discussion... but... without a reference object I prefer to be sceptical about labeling something as "false".

Thomas do you mean, in that test, there are true things which labeled false?

btw/ I track and enjoy your results very much.

[Kabe]

...besides, someone should thing refraction always as a question of boundaries. There is no...

glass(out)>
water(in)>


because it means:
glass > air
air > water

...which is not the same as
glass > water

See the above fresnel graphs to realize that this is a major difference exspecially for the amount of reflection.

Kabe

[Kabe]

This is a 7z file; as it has the highest compression and I need to be frugal about server space. You can open the 7z file using the Power Archiver utility.

Unfortunately I can't because I'm on the Mac. You are spoiling your great efforts a little bit on this very last step by choosing such an exotic format - but seriously just a very little bit

If you could mail me the file, I could provide a zipped version on my server space. You have to be quick though, I'm leaving for a couple of days around noon.

Kabe

[Thomas An.]

Yes, I remember that discussion... but... without a reference object I prefer to be sceptical about labeling something as "false".

Thomas do you mean, in that test, there are true things which labeled false?

btw/ I track and enjoy your results very much.

Tom, I simply do not know That's all. You could be right. I just have no way of confirming it.
You mentioned the first column as false, but I do not know because there is no reference and we need to be careful when speculating...

For example. When my wife saw the Maxwell water glass above she thought it was wrong because she couldn't understand the shadow of the refracted cup. She thought that "my software is glitching" .... but then she saw the photo ... and it changed her mind.

How do we know we "think" something "looks" wrong ? What if it wasn't ?

That is why I believe it is best to do comparisons with real objects (as much as possible)

[Thomas An.]

Unfortunately I can't because I'm on the Mac. You are spoiling your great efforts a little bit on this very last step by choosing such an exotic format - but seriously just a very little bit

If you could mail me the file, I could provide a zipped version on my server space. You have to be quick though, I'm leaving for a couple of days around noon.

Kabe

Hi Kabe,

There are software out there that handle 7z files for the Mac:
http://www.zipzag.com/features.html
(This was a Google result)

Anyway, if you like you can PM me with your email and I'll send you a zip version.

-

[Kabe]

If you could mail me the zipped version, then I'm happy to host it. The point is that most people - me included-, need a rather major kick in the butt to install something to read in a single file.

I've installed Stuffit Deluxe here that unstuffs nearly everything in use on *nix, Windows and Mac. What's not in there, is exotic enough for me that I rather just leave it.

Thanks & Cheers

Kabe

[Mihai]

Would really like to try this using mental ray, but the 3ds file gives me the glass split in half like this:



Is this normal?

[Hervé]

a glass cut in two... am I dreaming that I am awake...?

[Micha]

Hallo,

I hope I don't missunderstand to much, but I have a problem with this method ->

My thesis, the IOR calculation is wrong here. The internal calculation of the glass shader is 1/ior glass (ior luft / ior glass) (so it is in Renderman shaders). If we want to get a glass-water surface, than we should use for the relativ ior this 1/(1,55 / 1,33) --> 0.85. The new ior for the glass shader is 0.88 instead 1.17 or? I have used a 1/.. more.

Sorry, my english is not good enough to explain my idea with more words.

[rivoli]

Hallo,
I hope I don't missunderstand to much, but I have a problem with this method ->

yes, you're totally right and the problem was addressed before. the correct IOR should be 0,85 (which is what i used to set up with other renderes), maxwell doesn't accept IOR below 0, so couldn't test it the way you pointed out.

anyway, this so called "hyrid" method (as described in the drawing) is totally wrong and doesn't produce accurate reflections/refractions nor caustics patterns.
as long as maxwell goes the most accurate method to model a glass filled with liquid is the one thomas explained earlier in this thread.
you may want to download the test scene he provided here:

Hi everyone.

I have uploaded the experiment scene here:

(2.13Mb)
http://mywebpages.comcast.net/ThomasAna ... d_Glass.7z
This is a 7z file; as it has the highest compression and I need to be frugal about server space. You can open the 7z file using the Power Archiver utility.

The archive contains:
1. The scene as a 3ds file
2. The scene as a 3dm file
3. Two photos of the actual setup
4. Brief instructions.

I will upload the results here when they are done (I haven't started doing the actual comparison tests yet). If anyone else is interested you can try too.

--------------------------
EDIT: A few more 7z utilities

• http://www.7-zip.org/ (freeware)
• http://www.zipzag.com/features.html

[/color]

[Thomas An.]

Mihai,

Yes I see it here. The glass mesh is in two for some reason.

You can't join the two halves ?

-

[Mihai]

Yes, I did Just setting up the render now.

[Micha]

Thanks Rivoli. Do you mean "below 1"?

Thomas way looks so complicated for me, but it seems to be the best way now. I would like to use the hybrid method with relativ IORs. Physical, I like to use border surfaces between mediums. A light simulation software like Maxwell should easy handle this surfaces.

Do somebody has posted this "not below 1" problem to NL?

Best way could be, if in every shiny/transparent material an extra ior of the environment could be set.