Animation : CD Reflection

[mouj]

hey there, could that (http://www.neilblevins.com/cg_education/aniso_ref/aniso_ref.htm) help ?

mouj

[Alex Morris]

Also dispersion.............the colours of the spectrum appear due to refraction. Think there is a Blur material plugin to cheat this. Otherwise Brazil and FinalRender handle it.

[ZeBoxx]

Actually, the effect is caused due to diffraction foremost.

Brazil r/s doesn't simulate these in any particular way, and I can't really think of any renderer that does.
A shader could be written, possibly.

cebas' Pro Optic Suite does have a CD surface shader :
http://www.cebas.com/products/feature.asp?UD=10-7888-33-788&PID=16&FID=108

Which might get the job done, but the example images are less-than-convincing. An actual user might have gotten better results.

I've had varied results using a normal mapping technique, making the normals of disc shape emulate a double cone-like structure, reflecting a rainbow-colored gradient.

[Is-boset]

try to use an anisotropic material, and use a hi res bump map of circles trying simulate the little grooves of CD surface.

[Marcel]

There was this very old Max tutorial once where the rotation of the camera and the CD were linked to the rotation of a colorfull texture map on the CD Object. Worked very nice if I remember correctly.

[ZeBoxx]

You might be referring to this :
http://web.interactiva.cl/~comercial_dtschile/tut2/

Which although looks CD-y, is far from what you'd really want.

[Marcel]

As usual the past is less good then I remember :)

But I am sure that something excellent can be made with this technique. It just needs better texturemaps and maybe some subtle glows...

[ZeBoxx]

Well, one of the less work-aroundable issues is with when you tilt the CD so that it reflects further towards the light source.

The spectral effect change from a radial-looking set of 'beams' to a circle, and does this in fairly specific ways that a simple texture map can't really overcome.

You could make multiple and blend between them, but you'd need quite a few to not make it look ugly :)

[Chris Thomas]

The only attempt I ever made for thus used a raytraced or flat reflection map, a very fine bump maps for the grooves and a radial gradient for the specular colour.

Map the radial gradient using the "normal" option, and fill it with quite a tight series of rainbow gradients, this makes the highlight change, so as the angle of your camera to the disk changes, so do its highlight colours.

Use the anisotropic highlight type and use a gradient to map its direction, this causes the highlight to curve and bend as it goes around the CD.

The issue you'll have with this is that it needs decent UV coords for it too work, in my case I made the CD by lofting a rectangle around a circle to give me the desired UV's.

I'll try and post an example shader if I can get the time ;)

[rikimountain]

did i already say thanks to you guys!!!
:buttrock: :buttrock: i know why i like that forum...
gotta give it a try... and i guess i`ll post the result, if its not too ugly...

[Chris Thomas]

Here's a quick re-hash of that material as I memeber it, hope it helps. Max 5.01

http://www.christopher-thomas.net/cd_example.zip

[rikimountain]

yeah baby!!!
it worked superb!!
jmonkey2000 - thx a lot man...
you owe me .. hahaha..
:buttrock:

[ManiaX]

hi, i'd like to create a cd in 3dsmax 4.2
how do i do this??

[Chris Thomas]

ask rikimountain to pass on the info ;)

CT

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