Paint With Particles, How?

[robrtt]

Hi everybody.

I have no idea how do this awesome effect from Thinking particles(3dsmax) for more than one particle:

http://cebas.com/products/feature.php?UD=1...8&PID=15&FID=93

So how paint surface shader with many particles without using ray sop or create any new geomery? Just in shader texture operations.

thanks!

[sibarrick]

Aren't we just talking attribtransfer here?

Transfer an attribute onto your surface and use that to mix between two shaders in vops.

Alternative would be to write a shader that uses a point cloud to check the proximity.

[robrtt]

Aren't we just talking attribtransfer here?

Transfer an attribute onto your surface and use that to mix between two shaders in vops.

25516[/snapback]

i think its more complicated problem. but i can be wrong.

Every particle collison creates a new layer, like on this animation:

http://www.cebas.de/products/images/thinking/paint.mp4

Real Flow 3 also has this effect:

From NextLimit site:

"Wet texture mapping (

[michael]

I think there is something different going on with the Thinking Particles...the particles are NOT painting the 'surface'...they look like they are hitting a point on the surface which becomes the 'centre' of a new shader layer or shader effect...simon's suggestion would work here I think....

[Mario Marengo]

How about:

1. Make the particles stick on collision, and transfer the surface's rest or texture-uv attributes, along with the hit time.

2. Save the stuck particles as a point cloud for each frame.

3. The shader is passed the current time, then walks through the points in the cloud adding the effect by proximity (either in rest or uv space, and using either a texture map or procedurally) and taking into account the time elapsed -- a reference vector can also be added on collision for controlling the orientation of each "painted" instance.

Seems doable I think...

[TheUsualAlex]

hmm... that looked similar with an fx that one of my coworkr did 7 or 8 months ago. This approach was actually using Houdini's curve and generate a small library of matte from the camera. Afterward, do a camera projection onto the surface. I'd imagine it being doable in Houdini all right...

[Visual Cortex Lab]

hm... all those videos.. sounds like some "challenges" for me to learn Houdini :) ... nice link.

let's show how houdini rocks by replicating such easy effects... c'mon...

/me goes to make his own tests....

cheers.

[Rafal123]

can't those effects be achieved using simple spherical ramps with some noise??

[sibarrick]

Here's what I was thinking, the particle sticks on collision and has a attribute in it that determines it's age after the hit.

In the shader you loop through all the stuck points (point cloud) in uv space you determine the distance from the particle, the age then determines the radius from the point. It's easy to make procedural rings from this information. Add some uv noise and you are done.

[robrtt]

your ideas sound great. i will try this

thanks everybody for help

[Daryl Dunlap]

11 years later....can we Paint with Particles in H16?

[jscarr]

<crickets>    

 

[HappehLemons]

I feel like this should get to job done,

 

http://www.orbolt.com/asset/Julian_Davidson::jnd_wetmap::1.0

 

Not sure if it works in 16, but the example shows literally a paint brush painting on a surface using particles among many other uses.