faking dispersion using the new blend material

[DaForce]

I did mention it was NSFW

[RErender]

Heh, just learned a new acronym a tad too late...

[vlado]

BTW - saved img in vrimg, then converted to exr. Opened in PS with fnord proexr - it doesn't like vraymtlselect channels at all. They were all black

You'll need to convert each of the channels into its own .exr file using the -channels option. Photoshop doesn't work with .exr files with multiple channels.

Best regards,
Vlado

[Paul Oblomov]

It is a plugin, that allow you to work with exr channels. Every other channel is fine, but vraymtlselect... It can be extracted in AE with this plug, so seems to me a glitch in PS plug.

[DaForce]

Heh, just learned a new acronym a tad too late...

haha yeah sorry about that.. should have made it abit clearer.

[Paul Oblomov]

So, it seems, there's no way of making believable dispersion Maybe somebody will write a shader ?

[vlado]

It is not too difficult to write a dispersive shader with the V-Ray SDK... it is requested a lot, so it may be coming at some point.

Best regards,
Vlado

[Paul Oblomov]

I wish I could be the first pre-pre-pre-alpha-beta-gamma-epsilon tester of this beauty

[plastic_]

I hope this makes sense... This scheme can also be adapted to include intermediate colors of the spectrum, if you think a bit more. E.g. if you want 4 colors in the spectrum, you can do something like this: have the bottom-most material with 50% red color; the one above it should be 100% red and 50% green, the one above it should be 100% green and 50% blue, the one above it should be the base material. It's possible to maybe write a script for this...

Best regards,
Vlado

hi vlado,

i managed to do it with 3 colors, but i tried to use 4 colors as you described and it doesn't really work. can you please have a look:

(i am using 3 posts because i can only use 4 images in 1 post)


this is a single glass material with caustics:

[plastic_]

this is a blend material with IOR variations of the above glass material. it looks right and nice.

[plastic_]

and this is where i have a problem:
--------------








am i using the wrong color values, or isn't it working that way with the blend material?

[pixelstudio]

Wellll then some1 should write a shader...... hmm how is that done?
i have just started programming with the 3dsmaxSDK and the vraySDK for a month now, and now i'm only able to write custom meshes, do simple stuff to objects and such.. so writing a shader is to hard for me.

i have no idea where to start off, it would realy be awesome if some1 writes a guide on beginning you own shader using the vray SDK.

About the dispersion shader.

If you google dispersion and you click the renderman poorman's dispersion shader the it should not be very hard.

The technique that he uses is instead of casting 1 ray, it's casts 3 rays wich will be RGB.
That does not seems to be hard to implement but like i said. i have no idea where to begin hehe.
more info is on : http://astrofra.com/weblog/index.php...r-rman-version including the source for this.

a quick note, like he mentioned it's far for "physical" correct but well, should be fun if some1 is able to get it into a vray shader.

[stilgarna]

a quick note, like he mentioned it's far for "physical" correct but well, should be fun if some1 is able to get it into a vray shader.

Sometime physicall correctness is useless


Best regards

[stilgarna]

It is not too difficult to write a dispersive shader with the V-Ray SDK...

Ok but sometime pleople are unable to do this kind of operation... Even if it seems to be "simple"
Sorry if I'm a stupid guy with no brain and 2 left hand

A difraction shader would be great for many people... and 2 ways for this will be great. A poor way like the Renderman shader and a rich way with a lot of xeon and RAM.



Best regards...

[Fekta.studio]

Hi. here is a test I make for glass dispersion inspired from maxwell disparsion aberration materials mode and this tread.. need more work on shadows.

And what is happend with coustics? its shows up in "coustics preview" but not in main render
sorry for the crappy render. need time..
dunno witch material is "physical accurate" if any, but look promising to me so far..actualy I'm using calcium fluoride (CAf2) ,IOR Arachi and glass asf9 form IOR material database of maxwell as a reference.

But maby Im side track, any help and tip will be appreciate for coustics and mat settings.

ok some scene info: vraylight material set to subd: 200, no store with IR
properties for light coustics: set to 3000 subd. and multy 1.0, intensiity : default image set to 110,

IR: is set to high no other settings, second bounce is brute force, coustics is ON and set to multy: 1.5, search distance is 7.5cm, max photons is set to 600, density is 0.0

no sky no SUN just plane VrayLIght