Copy attributes from 1 to many

[pixelgate]

Hi

I'm very new to houdini. I've started learning a few days ago and made my first scene.

I paint the size of the objects. The objects are built in a few steps.

Now I got a problem:

After a sphere, some tubes are copied on the spheres. But the tubes are not scaled correctly. One step before, I could solve the problem with a attribcopy node because tsource and target points had the same numbers.

Now I need to copy pscale from 1 to many points. How could I achieve this?

Best regards,

pixelgate

[SpencerL]

Hi

I'm very new to houdini. I've started learning a few days ago and made my first scene.

I paint the size of the objects. The objects are built in a few steps.

Now I got a problem:

After a sphere, some tubes are copied on the spheres. But the tubes are not scaled correctly. One step before, I could solve the problem with a attribcopy node because tsource and target points had the same numbers.

Now I need to copy pscale from 1 to many points. How could I achieve this?

Best regards,

pixelgate

you can use a point() expression to lookup a value and apply it to your many objects. Add a point SOP to your target pts and in the 'pscale' value, point("../tsource", 0, "pscale", 0)

That will look at the pscale value of the point number '0' on the SOP "../tsource".

Hope this helps

[gaurav]

You could also create a point group using your source point. Now in the attrib copy sop specify just that group as a source.

It should copy the attribute to all the points in your input geometry unless specified a destination group.

Creating selection using group sop is a very powerful and flexible way of working. You may want to explore it further, if you are new to Houdini.

Cheers,

[pixelgate]

thank you SpencerL and vectorblur.

I forgot to say that I need to have multiple "one - to many" point selections.

Here are two screenshot to explain the problem better. I could copy the point attributes from the base points to the "toppoints". But now I got one "toppoint" and multiple points around it. These points need to have the same scale.

I have tried a few things with attribcopy and attribtransfer but neither worked.

SpencerL's solution could work here but I have no Idea how the expression should look like.

I image dummycode like this:

For each point $PT, point("../toppointgroup", "$matching toppoint", 0)

best regards,

para

[Macha]

If you use a copy sop then an attribute called pscale will automatically be picked up and used as a uniform scale.

Otherwise you could perhaps use a detail att on the spheres and set it to the same values as those on the tube and when you merge the whole thing ino one geometry you promote that detail att to points (otherwise they'd get lost)

[pixelgate]

I could solve the problem.

I just needed to delete the copy sop, made a new one and pre-attach a attribtransfer node. Perhaps, I had some "bad options" turned on the original copy sop.

Here is the render:

regards,

pixelgate

[freaq]

I could solve the problem.

I just needed to delete the copy sop, made a new one and pre-attach a attribtransfer node. Perhaps, I had some "bad options" turned on the original copy sop.

Here is the render:

regards,

pixelgate

that looks pretty cool

keep up the learning!

[Fabiano Berlim]

Very nice!

Try to use a box with edge cups as your ground, so you prevent light rays to overlap.

Edited March 27, 2012 by Fabiano Berlim

[R3.]

Very nice result! I'm still learning, too. Could you upload a sample scene file?

Thx!