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pclaes

particle erosion file

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Hi,

This is a file I put together to show how I did the erosion effect two years ago. I was asked if I could share the hip so here it is. It's been a while since I did that and I lost the original file so I rebuilt it.

It's not that hard to do, basically it's all driven by a sopsolver and some particles.

The particles collide with the surface and "erode" and "deposit" a bit of material. I visualized it using red and blue. Blue was eroding, red was depositing.

So initially the particle is empty and ready to pick up material, so it starts of blue. When it collides a trigger occurs and the blue starts to go to zero and the red starts to increase, after a while the blue is zero and the red also starts to go to zero, this suggests the particle has evaporated and deposited all the material that it has picked up. In the meantime the particle has been moving over the surface and it has been transferring those colors to the surface inside a sopsolver in dops.

Those transferred colors are driving displacements. Blue will represent the amount of inward displacement, red represents the amount of outward displacement. And when you mix in some noise in the displacement shader at rendertime, driven by the color, it gives a fairly interesting erosion effect.

It is important to not just erode, but also deposit material to make it more believable, that mass needs to go somewhere. And the shape of the erosion and depositing can change based on the forces you apply to your particles. You could also do this completely with volumes and build an isosurface from that volume. That way you would be able to carve out holes in the mesh rather than just displace the surfaces.

I did not do the shader, but that is easy enough, just use the color to drive the displacement amount.

Have fun learning.

Edit: let's see if I can input the vimeo too:

Guess not...

http://vimeo.com/24145987

particle_erosion_02.hip

Edited by pclaes
  • Like 3

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Neat, I like it Peter!

Edited by Macha

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Thanks! Will definitely come in handy.

Matt.

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Always good jobs from peter! It's amazing, thanks so much for sharing^^

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thanks a lot for sharing this! extremely helpful (getting back into houdini at the moment) and interesting going through your setup, changing up things, etc etc

cheers

chris

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sweet example, btw if u want to embed a vimeo video in a post just put

[media]vimeo url[/media] tags

Edited by ikarus

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Glad you guys like it.

Cool! Didn't know about the "media" tag.

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hi Peter!

thanks for sharing the file with us. I had just looked at this post lately... But I was wondering how do we bring the color to the shop for the displacement shader to be able to use it? I am always confused how to bring those information across dop, sop, shop etc.. Do you mind to show us how please?

its always fun learning from you.

Shandy

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Hi

I just got the shader to be working. If any of you guys were wondering and have no idea like I was before about how to do the shader, here is the file.

Thanks to Erik JE to help me out as well. :)

particle_erosion_01.hip

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