Glass colour and refraction

[jim_tim]

Can somebody tell me why the materials created in the panton chair tutorial in the training manual appear clear when applied to objects outside of the tutorial?? I saved the materials as vismats but when i apply them to objects I have created (or 3d warehouse objects) they lose their colour and just appear as clear glass.

Cheers.

[Jackson_cg]

Re: Glass colour and refraction

Screenshots please.

[jim_tim]

Re: Glass colour and refraction

How do i insert a picture directly into the view?...... I clicked insert image but nothing happened

[jim_tim]

Re: Glass colour and refraction

This may do it ???

[jim_tim]

Re: Glass colour and refraction

Both chairs above have the same green material applied to them. However, as you can see only the panton chair retains the green tint. This has happened on quite a few objects I have tried to apply this material to.

[Jackson_cg]

Re: Glass colour and refraction

They are both green- look at the edge of the middle chair. VfSU fog takes into account the thickness of materials (more specifically the distance between where light enters and exits a volume) so the thicker panton chair looks greener than the middle one, just like glass does in reality. You have to adjust the Fog colour and multiplier to get the effect you want for different sized objects.

[edonk]

Re: Glass colour and refraction

Jacksons right - you can also clearly see parts of the thicker chair (right hand side) which are see through as it becomes thinner. Check the fog settings.

[jim_tim]

Re: Glass colour and refraction

Guys thanks for the advice but unfortunately i dont think you are right on this occasion. I have significantly increased the fog and you can clearly see this with the panton chair but the other chair remains clear. I think the green that you speak of in the clear chair does not suggest that it is green, but it is reflecting the green of the panton chair somehow.

I don't understand lol ???

[Jackson_cg]

Re: Glass colour and refraction

OK try this:

Delete the pantone chair and the orange box and set the background to light grey. Now increase the scale of the middle chair by 10x, render and post a screenshot.

To be honest VfSU Material refraction settings are extremely complicated (almost all the parameters interact with each other), even the most in-depth V-Ray guides tend to only brush the surface so it's very difficult to diagnose or fix problems from just an image. If you post the skp file using Rapidshare I can take a look at it for you.

[artupato]

Re: Glass colour and refraction

for objects with the same color and settings but differ in the volume(with fog color), the result would be different right?
i can see the green edges of the middle chair. jackson is right.

[jim_tim]

Re: Glass colour and refraction

Yes they would differ indeed..... but my problem is that they do not differ. The chair to the left does not retain any fog what so ever. That small bit of green which you have spotted on the clear chair is the reflection of the panton chair. Should I change the panton chair material to a blue colour for example, the clear chair would have small bits of blue on it.

I'm just not sure why - no matter what value of fog i put into the chair - it remains clear.

[jim_tim]

Re: Glass colour and refraction

There's the file:

http://rapidshare.com/files/34534463..._wood.skp.html


cheers Jackson ;D

Appreciate the help

[Jackson_cg]

Re: Glass colour and refraction

Uughhh, Rapidshare's damn servers are overloaded. I'll try downloading it again later.

[Jackson_cg]

Re: Glass colour and refraction

I took a look at the model, you broke the first rule of CAD modelling/rendering: ALWAYS make sure normals are facing outwards. Your middle chair had reversed faces so it was impossible for V-Ray to calculate fog. You should frequently switch between textured and monochrome render modes in SU to ensure that all normals are facing the right way. BTW, that middle chair was extremely high poly for using in SU, I crunched it in Deep Exploration (MeshLab is also good and free) to 5% of the polys and it looks almost identical.

Hope this helps.

[edonk]

Re: Glass colour and refraction

Nice to see a solution, good one Jackson!
Also I'll check out meshlab...