i3d image coloring

[red4kat]

Hello Everyone,

Reading your posts reminded me of the question (struggle) that I had earlier about creating a good looking fire/smoke and other effects. I worked through the tutorial they have in the sideFX apprentice (the one with the mushroom cloud) and it turned out to be all nice and dandy but...

one thing I had trouble with. That's to create a shader or group of shaders the similiar way but with different colors so that they blend into each other but still you can distinctively see the separation of colors. I think that would be an answer to some of your questions, Szymon, that you posted about the explosion or fire earlier. I tried attaching the point SOP to metaballs and put some expressions in the color parameter. I also tried creating two separate systems of metaballs with two different shaders with different colors. Still they all blended into one color and that was all. I just know there must be some kind of a way to make them separate, but... I haven't figured that out yet.

Anyone has any suggestions?

Thanks,

Kat

[red4kat]

Oh, sorry, forgot to mention that I was using the i3d cloud shader attached to mettaballs. Which also reminds me of another question I have. Can you use i3d image with any other geometry then metaballs? Can you use it with plain particles?

Kat

[plan9]

kat wrote:

"a shader or group of shaders the similiar way but with different colors so that they blend into each other but still you can distinctively see the separation of colors."

if im understanding this correctly, you want something like a ramp shader, it would perhaps use an alpha channel to kill hard edges? (assuming you want an explosive look), it would depend on your understanding of shader writing & VOPS. you might want to consider rendering layers of detail and bringing the data into cops for the final result, you can achieve some nice effects without having to deal with mountains of code...read up on deep rasters!

"Can you use i3d image with any other geometry then metaballs? Can you use it with plain particles?"

in the i3d ROP there are options within the, "render as" field. "use meta/particle geometry" might be what you are looking for.

[red4kat]

Ok,

Thanks plan9, actually what I meant was not the color ramp but random color variations. Like when you create particle system, add color POP to it and in the parameters write expressions like rand($ID). But I should go and play with it some more. Will let you know if I discover something cool...

Kat.

[red4kat]

Ok,

so what happens is that no matter what color expressions I put on my particle system that I want to render it still renders them in white or the color that I specify in the "fog color" parameter of the v_texfog1 shader and just to make my life more difficult that parameter won't take any expressions. In the old days, when we could just create a regular material constand with alpha without any colors, it would render the particles with the colors that I could specify in the pop color parameter. But not with i3dimage or I am doing something wrong.

[aracid]

hey all

color metaclouds ?

how is this done ?

over time or via ramps.

any ideas

i would assume that one would export the variables in ur custom i3d shader, and to bring it back in, would u just modify the standard fog shader to incorporate the "exported color variable" back into the color of the fog shader?

if this is the long route, could someone throw 20cents this way

all the best

aracid

[doc]

any ideas

i would assume that one would export the variables in ur custom i3d shader, and to bring it back in, would u just modify the standard fog shader to incorporate the "exported color variable" back into the color of the fog shader?

You got it, have a look at the vex function "mattrib" (it's called "metaball attribute" in VOPs)

you can use this to write out your own attributes to i3d(from you i3d shader).

then you can use "texture3d"(same name in VOPs) to read this attribute in your atmosphere shader.

All the best

Luca

[aracid]

hey doc

thanks for the info, Ill give it a try :-)

all the best

aracid

[Marc]

whats with all the resurrected posts? It's like night of the living dead in here.

[TheDunadan]

whats with all the resurrected posts?  It's like night of the living dead in here.

15020[/snapback]

... and it's past halloween :bag:

Jens

[doc]

BRAAAAINS..... BRAAAAINS.....

[TheUsualAlex]

DId you forgot Pinky too? Or was Pinky the one who keeps on saying

BRAAAAINS.....  BRAAAAINS.....