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varomix

Painting with polygons

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Who isnt gonna try this out right now :)

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I saw the presentation at siggraph and it was interesting.. but I felt the approaches the Disney Feature team developed for Bolt (which was presented just before this one) were stronger. On Bolt they painted two textures for everything, one very detailed and one loose and more painterly. They used simple tricks like depth from camera, Y-height, in shadow or not, to trigger the transition between the two texture maps. To get a painterly edge to objects the used their fur system to construct a series of cards on the surfaces of objects, each card was then textured with an opacity map of a few different brush strokes. (me thinks of a copySOP with a stamp...oh the joy). A simple raytrace was done to accumulate the opacity of on the surface and the result was used to generate an image at render time. Simple, a bit expensive, but still achievable and very stable to generate the appearance of brush stroke edges.

Neat.

-k

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thanks for sharing that varomix!

I didnt take it too far but to get the first step I just used a vop sop to displace N with noise and pass the same noise to velocity. Then use geometry motion blur and adjust camera shutter time to taste.

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wow, a very great aspect to do such things.

would be great to see something who came up with a houdini solution.

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thanks for sharing that varomix!

I didnt take it too far but to get the first step I just used a vop sop to displace N with noise and pass the same noise to velocity. Then use geometry motion blur and adjust camera shutter time to taste.

Thanks Michael that put me into the right path

and did this

post-3040-125071186424_thumb.jpg

is getting there, but now, what if those velocity vectors where not straight? , what if there would be a way to bend them, twist them, curl them, ooh that'll be awesome, and I know I've seen this before for fur.

If anyone can help on the velocity vector bending, please do, this is where houdini takes off :D

thank you

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I'm confused. If you're using geometry motion blur, then why would the velocity get used?

As an aside, those pictures on the website just look like jittery, motion blurred edges to me ...

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I'm confused. If you're using geometry motion blur, then why would the velocity get used?

As an aside, those pictures on the website just look like jittery, motion blurred edges to me ...

Now I'm confused :D

I'll just sleep on it and I guess by morning you'll have a sample that will blow my mind :D

or not

seriously, if you have some tricks, please share, I'm doing some fur tests

post-3040-125074049048_thumb.png

Cheers

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I'm confused. If you're using geometry motion blur, then why would the velocity get used?

Is there another way to non-uniformly blur static geometry? Actually the Houdini semantics confuse me wrt "transformation" blur & "geometry" blur, but I was referring to geo_velocityblur :blink:

As an aside, those pictures on the website just look like jittery, motion blurred edges to me ...

which just goes to show, one man's jittery motion-blurred edges, another man's brush strokes. Or something like that.

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I didnt take it too far but to get the first step I just used a vop sop to displace N with noise and pass the same noise to velocity. Then use geometry motion blur and adjust camera shutter time to taste.

Thanks Michael that put me into the right path and did this

I'm not understanding Mike's tip - I can't seem to get this effect to work that way. Could someone post a screen cap of the VOPSOP or a hip?

Edited by geneome

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Did a test this side and just uploading for those that requested some help to get started.

Thanks rende! Just what I needed!

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I'm curious what renderer they used. And even more curious, what kind of motion blur. Because with realistic looking motion blur you don't get that effect. It looks like a simplified, real-time, onion-skin sort of motion blur... (I've tried a few months ago in both maya and houdini, with several rendering engines and different types of motion blur, but none looked ok).

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Hey everyone, I know this thread is old. But as I was trying to pretty much replicate this effect earlier in the week I stumbled upon it.

I at first had built the motion blur through VOPS and with controlling velocity vectors, but I wanted to more accurately match the effect of the site, so I took another look at their video and thought about it for a second.

If I take a noise, add the noise as displacement in a VOP SOP then we are distorting due to noise. A noise vop like Anti-Aliased Flow Noise has a position vector for the noise generation. Use a matrix rotate and a vector orient on the position of the object for what goes into the noise and ever 2pi you have the same noise pattern.

output.864.jpg

<- in motion

So in their version they animate the displacement so that it matches the original position each frame, houdini didn't like that as much so I made it rotate 3 times per frame and set the xform and geo motion blur samples to 4 or 5

(HINT: Due to data types and rounding and suchnot, 2 * $PI * $FF does not work once the frame number gets really high. Instead use ($FF - $F) * 2 * $PI to get the distance the current sub frame is away from the nearest $F. Really quickly it works out, though again I made it something like ($FF - $F) * 6 * $PI.

For the shader I did similar things, but I'm not really going to go into it too much. Mainly I just set up a ramp that runs off of a distorted version of the shading model coming out of a, well shading model.

I'm using Houdini 11, though the motion blur should work on early versions the shaders just really won't.

If anyone wants my hip file here it is: but I didn't really clean it up for everyone so I can't guarantee how easy it will be to decipher. I know I know, I should comment better.

If you have any questions feel free to email me (I'll get those much faster than checking the forums) at gaviteros[at]gmail[dot]com

Else wiseee: here you go!

HIP File

EDIT: I was informed that the hip file was broken. It should be better now, i have tested downloading it to another computer and it worked. If anyone finds any other problems please email me. :D

Edited by Gaviteros
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