vikk
April 18, 2008 14:29:10
hi friends .
how do i create clouds in houdini. which are the different ways . i dont want to show movement too much. movement will be settle but i am planning to do some object interaction with clouds.
if you have any idea how to deal with this plzzzzzzz. help me.
cheers
vik
old_school
April 21, 2008 06:39:35
If you search this and the OdForce forum for clouds and/or smoke you should find quite a few solutions posted. I believe there was a post on OdForce just last week.
As for rendering clouds, you will want to look at rendering Volume primitives with Mantra as your first method.
You can pass metaballs as volume primitives in to Mantra by using a simple toggle on the object “render metaballs as volumes…”.
You can model any geometric form and then pass this geometry through an Iso Offset SOP and at the top convert to Fog Volume.
Apply one of the smoke materials to your object.
You can also use i3d 3d voxel maps and fog objects as a second method.
For mid and far ground clouds you can get by with texture mapped cards and planes.
rdg
April 21, 2008 09:36:49
You can pass metaballs as volume primitives in to Mantra by using a simple toggle on the object “render metaballs as volumes…”.
I didn't know about this one.
How do volumes refer to restPositions - do they - or is this a completely different world?
http://www.medikalesha.de/spool/cloud.php [medikalesha.de]
old_school
April 21, 2008 09:39:42
A good implementation of this can be found in the FX Tools Heavy Smoke Digital Asset. It uses Metaballs as volume primitives.
If you don't know, you install the Fx tools through the “+” menu at the right side of any tool bar. From the popup choose to install and from there you will link in to the SESI Exchange. Choose the FX tools. Now you will have the FX toolshelf.
rdg
April 21, 2008 10:13:26
no - I didn't know.
Thanks.
rdg
April 21, 2008 11:01:18
billowhispysomething - the shader I used - expects a rest position.
while the shader from the fxtools uses a P from the metaballs converted to objectspace and no rest.
but trying to use this shader didn't help:
http://www.medikalesha.de/spool/cloud2.php [medikalesha.de]
I must still be missing something.
Gerome
April 22, 2008 11:10:49
Look at this file… the setup of the shader is busted, but with playing the parameters you should get some nice cloud. My version4 was fine but I lost it.
it is a cloud of particles in POP and I attached some metaballs to it. Have a look at the setup. Dont forget to recook the geo in SOP and get the shader to point to the geo file.
In POP you can do some interaction with your particles.