I3d Smoke-control :)

[Val]

who knows how to make i3D smoke dissolve over particles life?

( can I use colorPOP to do that?)

if some one can show me simple file... will be best explanation!

thanks.

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Val

[Val]

wrong alarm.

(I found work around)

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Val

[MIguel P]

I also wont know this!!!

[Visual Cortex Lab]

yeah would also like to know this

[Val]

hey.

I still 'researching' -best way..

Idea is

to render 2 passes, one with i3D

and one with metabols-RGBA..

then in digital fusion use 'channel boolean'

or in nuke - 'shuffleCopy'

to get ALPHA from metabol-RGBA ...

(or transfer any channel.. to colorise smoke)

this way you can color or dissolve smoke based on particles AGE or LIFE

I attaching simple test, I was playing yesterday to see if works..

for me looks promising and I will keep working

to get nice details on i3D-smoke.

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Val

[Val]

this is example for coloring based on particle age.

(maybe it is not the best way.. but I do not know another way)

I will keep testing-playing...

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Val

[HyFrmn]

I would imagine you could edit the default vex metacloud shader, to write an additional color channel, that could then be read back in to color the i3d's on final render. I havn't tried this but I believe something like this is possible.

~MP

[Val]

I would imagine you could edit the default vex metacloud shader, to write an additional color channel, that could then be read back in to color the i3d's on final render. I havn't tried this but I believe something like this is possible.

~MP

27682[/snapback]

Hi HyFrmn.

thank you for reply!

I am new to houdini..

and discovering how to do staff..

I do not knew I can edit that shader.

I was thinking it is possible just transfer Cd to i3D,

I did search, and

and find this:

http://odforce.net/forum/index.php?showtopic=3998&hl=

no one reply, and I start thinking it is not possible, and I start

thinking another way to do this

I will try to do...

Thank you very match for pointing correct direction!

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Val

I find tutorial!!!

http://www.odforce.net/tips/shader_wiritng_i3d_2.php

[sibarrick]

This is definetely possible, and not "too" difficult. People keep asking about it. I have an old file I keep digging out, so I'll try and clean it up at some point and post it.

[MIguel P]

And... How to transfer de Cd attribute from Color POP to the metaballs? In houdini help there is a tutorial that says how to transfer this, but the resulting colored spheres haven't go specular.

[Val]

[quote name='MIguel P

[MIguel P]

hey MIguel P

[Val]

[quote name='MIguel P

[Val]

This is definetely possible, and not "too" difficult. People keep asking about it. I have an old file I keep digging out, so I'll try and clean it up at some point and post it.

27688[/snapback]

Hey.

yes.. I did tutorial from odforce, and I am very excited

and happy with 'control' over shader.

When I get good at doing this..

I am thinking about not telling others.. :D:D

like other users do (JK)

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Val

[MIguel P]

try with  attributeSOP and convert Cd to diffuse..

or add shader (superMaterial or layeredSurface),

and render.

27725[/snapback]

Thanks!!

[SvenP]

Hey.

yes.. I did  tutorial from odforce, and I am very excited

and happy with 'control' over shader.

When I get good at doing this..

I am thinking about not telling others.. :D:D

like other users do  (JK)

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Val

27728[/snapback]

Its not that nobody wants to tell you . Just getting color information into and from an i3d file is simple (ive attached a file to show you how simple it is ). The hard part starts with getting your clouds to render with realistic scattering and shadows and thats not something someone can explain you with 10 lines of text and a simple hipfile and i think nearly nobody would do something like that with vops .

Sven

i3dExample.hip

[Val]

thank you Sven

I start learning houdini few month ago...

I do not even know if it is possible or not,

just trying to find info-help-tutorials....

( hmm.. I think, I do not put you in my black list..

I will make final decision after checking your file

thanks again!

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Val

[MIguel P]

Thanks Seven! But in this example the color isn't of a color POP.

[Val]

hey MIguel P

[lisux]

The color info from a Color POP is in the Cd attribute.

When you import your particle animation to SOPs using MergePOP you get this, and the rest, of attributes.

You only need to knoe how to read this attribute in a i3D Shader, you can use the mattrib function to retrieve info from the metaballs to you i3d texture.

Be careful about the corrd space you use, it depends of the effects you want to use.

Useful links in the houdini help:

hdox://houdini/content/vex/contexts/image3d.html

hdox://houdini/content/vex/vex_cat_i3d.html

Good luck