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raylistic
07-07-2008, 10:23 PM
Hi, I am using the fluid example included call stormy clouds. Is it possible to make the clouds swirl in the center or affect them using the vortex field? How do i do that?


Thanks,
Ray

raylistic
07-08-2008, 05:28 AM
Any idea, anyone?

raylistic
07-08-2008, 03:08 PM
According to the notes given:

This fluid creates a bank of volumetric cumulus clouds.
There are no grids used, just the internal fluid texturing.
Instead of using self shadowing (which is slow to render) the color is a textured Y gradient that loosely model simple self shadowing.
A similar texturing on incandescence helps simulate the blue ambient sky lighting.
The effects of atmosphere are handled by a second fluid "skyFog", and volumeSamplesOverride is set to 4 to provide better depth integration between the two fluids.
The general density of clouds can be controlled using the opacity Input bias, and the scale of the clouds with the texture Frequency.
If one wished to paint the cloud regions then a density grid could be used.
Set density to grid and change the opacity input from y gradient to density.
Textured clouds will then appear where one paints density.
The clouds could be animated effectively by keying the textureTime and possibly the texture origin.
A SpaceTime noiseType may also provide a better animated effect than Perlin.
If one wishes to swirl the clouds animating the coordinate grid will work.
To do this set the coordinateMethod to Grid and the density to dynamicGrid.
(The density currently needs to be on, although you don't need to define any density) One can then push the coordinates with turbulence, velocity gradients or a dynamic velocity grid.
This node is still slow to render, so one may wish to try rendering in hardware instead.
There are no used grids on this node, so increasing the resolution only affects the hardware draw.
Simply scale up the resolution (for example 240 16 240) and render in the hardware render buffer window.
One may get better hardware results by using an imageplane background and hiding the skyFog node.

This is taken from the stormy clouds fluids library.
Any idea on how to animate the coordinate grid?

Scob
07-08-2008, 03:46 PM
Hi there ,

Probably you can check this :
http://area.autodesk.com/index.php/blogs_duncan/blog_detail/volume_displacement_method_for_clouds_using_fluids/

It s from the (autodesk) Duncan Brinsmead Blog ...
Awesome stuff inside , thanks to him for his amazing work !

Cheers

Aikiman
07-08-2008, 08:49 PM
Try painting some velocity in circular motions may help you some, you need to set grids to dynamic.

raylistic
07-09-2008, 02:33 PM
thanks guys. looking into them now. =D

Duncan
07-11-2008, 06:59 PM
Set Coordinate method = grid, coordinate speed = 1, and velocity = dynamic grid.
As mentioned paint some velocity then set initial state to get a push. Or you could use a field. A vortex field could work, or you could use a drag field: keyframe the rotate of the drag field and make the magnitude around 20 and inheritVelocity = 1. With fields you may wish to key the magnitude to zero after a few frames to allow the simulation freedom to swirl and such.
Duncan

raylistic
07-22-2008, 02:51 PM
Set Coordinate method = grid, coordinate speed = 1, and velocity = dynamic grid.
As mentioned paint some velocity then set initial state to get a push. Or you could use a field. A vortex field could work, or you could use a drag field: keyframe the rotate of the drag field and make the magnitude around 20 and inheritVelocity = 1. With fields you may wish to key the magnitude to zero after a few frames to allow the simulation freedom to swirl and such.
Duncan


Thanks alot duncan, sorry for the late reply. Thanks for the help!

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