I3d Experiment

[Symbolic]

Hi,

I am trying to render an i3d teapot...

I have the teapot created out of metaballs... and the workflow follows as below:

model (metaball teapot) -> export shader: VEX Meta Cloud (default) -> export MANTRA: 3D Texture Generator ( creates the *.i3d file)

then

A FOG object pointing to the *.i3d file (isoSurface) -> import shader assigned to the FOG object: VEX 3D Texture Fog (reads in the *.i3d file)

I do not know what is wrong... but it is a messy workflow... and it is either slow... or blank... something is wrong.

Here is the file:

cloud_teapot_end_v11_post.hipnc

Thanks for any help.

[Symbolic]

...I am confused about:

Which shaders are used for creating *.i3d?

Which shaders have to be assigned or linked back to the *.i3d file later?

At what level we give the shape of the clouds... at the shader that is exported as *.i3d? ...or the shader later linked to the *.i3d?

Thanks.

[Symbolic]

This was one of the results that I got at some point...

I do not know how I got it:

[Tamis]

I have the same issue, gave it a rest.

i know it's a surface shader, don't know how it's done tho.

[Symbolic]

I gave it up for now...

Never was able to create nice clouds!

If somebody knows a better technique than i3d... please help...

or any workflow help related to i3d would be a great one...

cheers.

[diana]

do you have an add node in the fog obj? put the render flag on add SOP, turn off the tea cup obj, try render again. is your clouds density too high?

[Jason]

You could try using some Metaballs for the rough modeling layout -> IsoOffsetSOP (FogVolume/Metaballs mode) -> VolumeMix (User mode with expressions like sturb($X,$Y,$Z,2).

[Symbolic]

do you have an add node in the fog obj? put the render flag on add SOP, turn off the tea cup obj, try render again. is your clouds density too high?

to be honest... I really do not know what was on or off... what is the add node for? I just remember to be very disappointed and confused.

If some one has a time... and post a sample workflow file some time... it would be a gret help... or suggest any other way of creating clouds.

Thanks for your interest in this topic.

[michal]

hi, I did a simple test and it looks a little bit better.

[Guest Swann]

Hi everybody

Some time ago on 3d buzz we did some tests with i3d and from what I remember it end up on on generating i3d file, then read with iso surface and add shaderSOP with VolumeCloud shader applied in surface, no fog objects and bouding boxes. Pretty easy and fast, and gives good results, from what I see here much better than this.

Check this:

I3d

Edited May 1, 2008 by SWANN

[Guest Swann]

And here are render examples.

EDIT: In all examples I3d texture resolution is set to 128x128x128.

Edited May 3, 2008 by SWANN

[Symbolic]

hi, I did a simple test and it looks a little bit better.

Hi michal,

This looks much much better. What is your workflow... Could you post a file?

Thanks!

[curveU]

hi, I haven't tried it yet, but I know there is a tutorial in the old Houdini 8 document Volumetric Effect, do the similar thing.

[Symbolic]

Hey! Thanks. Thats a cool resource.

Cheers.

[nnnnn]

Hi michal,

This looks much much better. What is your workflow... Could you post a file?

Thanks!

Here is the file

cloud_teapot_end_v11_post_corrected.hipnc

[Symbolic]

Here is the file

Thanks alot. I will have a look.

[zasid]

Thanks Micheal for sharing the file .

[nnnnn]

I am not Michael

[MENOZ]

hello,sorry for the noob question.

in the SHOP context i see there is a billowy_smoke material. this is applied to the geometry that will read the i3d from disk.

what are the other two shaders? it seems they arent used. right? :bag:

[TheUsualAlex]

hello. Looks like the v_metacloud1 is used (by the Texture 3D generator), but the v_fluffy1 SHOP is not used, I don't think. What happen is that i3D file is generated from the metaball points using v_metacloud to determine how features are to be generated. Once i3D file is generated, the ISOSurface SOP is used to read the file in, which then that geometry has billowy_smoke shader attached for the volume rendering process.

Alternatively, you may also like to check out the Mantra: Image3D Volume Procedural to render the i3D too. I think this should a bit more efficient memory-wise (is this correct, someone?).