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kart19

Flatten clouds around a sphere

I'm running some tests on making clouds from data, to model around a sphere. The test renders are below. I was wondering if there is any way to use flatten command in the cloud node to radially flattening them. It is too fluffy now.

I have tried flattening the underlying geometry but that does not create the desired thinness. 

Also, I have used equirectangular satellite imagery of clouds to place geometry around a sphere. This geometry is the source for the cloud rig. If you have a better method of doing this, that would be great too.

I'm a noob to Houdini and I am figuring it out as I go along. Thanks!

Cloud_Fluffy_Low.jpg

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Generally when people do this shot they just use a card with the image of the clouds due to the distance from space you are at, as you can hardly see the depth. If you are flying in on the planet you'll just use a white dissolve as you hit the white cloud layer and miraculously appear on the other side due to edit cuts, as the physical passage of a camera through the cloud deck would take to long normally. 

If you flatten the image, we just used a one voxel sized simulation to get the motion to continue from the original source data. Then we kept the data as an image or geo to wrap it back on, and the convert it to voxels then with something like point to.voxel, but extremely dense to keep it thin. Make sure you cull the side you don't see inorder to increase density it you stick with volumes.

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Thank you so much for the response. Not planning to fly into the clouds, but wanted to stick with volumes and have it a little animated.

Could you explain the second part and how to go about doing it, complete beginner here. Thank you!

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Here is a very basic setup, where on the point vop you can apply the texture from your clouds, or the rendered out texture array of your clouds, or you could supply the volume sim of your clouds, or by default I used noise as a I don't have a cloud texture lieing around at the moment. You then can cull the points from the back side of the planet so you don't need to process them, plug them into a vdb from particle, and convert to volume to render in mantra. The more detail your cloud texture or sim reference is the better. 

PointsToVolume.hip

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