how to sharpen geometry (opposite of smooth)

[JoshJ]

I'm looking for a way to sharpen geometry, for example, choosing areas with more curvature and making those areas have an even sharper curvature, eventually becoming a sharp edge. I tried to play around with the measure sop and point clouds, but haven't yet achieved the effect.

There are some brushes in zbrush or mudbox that can do this, but does anyone have any link to a procedural algorithm or concept of how it could be done?

[brianburke]

here's a way to do this that i like. its based on:

http://en.wikipedia.org/wiki/Difference_of_Gaussians

its pretty simple really, just blurring your geo up, subtracting the point position of the blured from the unblured, then adding the result in to taste.

sharpen.hip

[Macha]

Wow, I like that method a lot!

[bunker]

Very nice, thanks Brian ! seems to work for volumes as well

Edited February 14, 2011 by bunker

[brianburke]

Very nice, thanks Brian ! seems to work for volumes as well

sweet, got any pics of that? i'd be awesome if you could pull 'mad detail' out of a fluid sim.

[bunker]

Here is a simple test on a lowres cloud ( volumeblur+ volumevop )

[JoshJ]

That's really excellent, exactly what I was looking for. Thanks Brian, and also bunker for the tip on volumes!

[bunker]

another test, on a lowres sim

[bunker]

The difference is even more noticeable in the render:

[old school]

Then try this technique on your velocity fields in a pyro sim in a Gas Field VOP.

And instead of adding back, multiply by itself and add back. Will sharpen the velocity fields and create all kinds of cool swirlies in your sim.

[brianburke]

damn, sweet

[Macha]

Then try this technique on your velocity fields in a pyro sim in a Gas Field VOP.

And instead of adding back, multiply by itself and add back. Will sharpen the velocity fields and create all kinds of cool swirlies in your sim.

I don't know how to do blurring in the gasvop, but I tried the sop solver.

Like that?

volsharp.hip

[bunker]

Hey Macha,

the best is to use microsolvers for that, so you don't need any SopSolver :

volsharp2.hip

You can do the sharpening calculation in one GasFieldVop, or with two GasCalculate.

It works, but since you sharpen the velocity on every frame, it gets really noisy quickly.

[Hazoc]

NNnnnice. Could be probably used for something like this too:

http://www.petershipkov.com/development/SOuP/videos/peak_liquids.mov

Turning blobby fluid meshes a bit crispier.

edit: Hmm well after a quick test maybe not.

Edited March 11, 2011 by Hazoc

[quarel]

The difference is even more noticeable in the render:

really nice!

[dyei nightmare]

The difference is even more noticeable in the render:

i fucking love this software and this forum

[lisux]

This technique is very cool.

Thanks for sharing

[old school]

NNnnnice. Could be probably used for something like this too:

http://www.petershipkov.com/development/SOuP/videos/peak_liquids.mov

Turning blobby fluid meshes a bit crispier.

edit: Hmm well after a quick test maybe not.

Oh you mean the old Peak SOP followed with the Smooth SOP. Check out the attached file for how to do this in Houdini.

sharpen_fluid_extreme.hip

[Davvechan]

On 2/14/2011 at 6:24 PM, bunker said:

Here is a simple test on a lowres cloud ( volumeblur+ volumevop )

Long time ago this post was active, but still interesting ideas that you guys brings up.

Could you specify more, what you did here? Currently I usually use the "volume convolve" to do sharpening.