Hi!!

How can i transfer for example the Cd point attribute from a poly sphere to the ISO version of the same sphere?

Thanks.

Use an attribute transfer sop.

Use an attribute transfer sop.

you can't “transfer” attributes from points to a volume. Volumes *are* attributes. You need to build it from a point cloud that has the attributes.

try using a volume mix
you'll need an expression similar to

point(“../trail1”, nearpoint(“../trail1”, $X, $Y, $Z), “v”, 0)
you'll need three of these, one for each component of the v attribute (assuming that it is v that you want to create).

You'll also then need to have a name sop to tell these volumes which attribute they are supposed to represent.

As much as I like expressions I am slowly converting to the vops side because of the gained speedup.

So can we do this with the volume_vop inside of sops or should we use a “gas field vop” inside of a new fresh field in dops?
I was recommended not to use the “gas field to particle” for this kind of stuff as you have little control over the sampling of the voxel (- in other words, it does not play nice with up-res).

A solution similar to an attribute transfer in vops would probably be ideal. So what would be a good equivalent of the nearpoint() expression - ideally with a distance/radius control?

Or would you recommend using pointclouds to help speed up iterating over the points? I would love to know how the attribute transfer works on a vop level.

Thank you allegro.

Its possible that you post a hip file?

thank you.

Allegro
you can't “transfer” attributes from points to a volume. Volumes *are* attributes. You need to build it from a point cloud that has the attributes.

I implemented exactly this in a little file which will probably help quite a few people trying to “transfer an attribute to a volume”.

It uses vops and the point clouds within them -you have a bit more control through the radius settings on the attribtransfer sop. You can speed it up -at the cost of accuracy - by setting the maxnumber of points on the volume vop to a lower number.

hope it helps, if anybody knows a faster way, please post a file.

Thank you peter…. and congratulations for your awesome reel, i have your DVD from 3d Buzz and is great!!!.

Thanks for your comments and support.

I'm in the process of converting that example into a digital asset - so you almost have a “atribute transfer sop” from sops to volumes. - and so it works with scalar and vector volumes, float and vector attributes.

If you combine that with the wet maps/sop solver digital asset that Jason made in this thread:
http://forums.odforce.net/index.php?showtopic=8990&hl=erosion [forums.odforce.net]
with this asset:
http://www.sidefx.com/exchange/info.php?fileid=613&versionid=613 [sidefx.com]

You can get some pretty cool results I think. – Well at some point you are building a simplified version in sops of what really is done inside of the solvers in dops.

The main reason I want to transfer attributes is to define those volume fields so I can feed them into the solver. Link this with some of the trail tutorials on my dvd and you get some sweet possibilities.

Example of what I am currently working on: emit particles, give those particles curves as trails, attribute transfer color as fuel, or tangent vectors as velocity (or both) to volumes and feed it into dops to drive fire that climbs(/ignites the fuel) along the trailing curves of the particles. (The curves can be resampled and are basically there to avoid having to do a huge amount of substeps to get enough points for smooth trails in fast moving particles.)

Anyway, when it's done I will post some of this here or on odforce, might put that asset on the exchange.