Hi,

On a CHOP i'm trying to use a user generated float attribute on points (SOP), to drive a delay on channels (tx ty tz) in a CHOP, but i can't find right way to do it.

On the geometry node i import the t pos in animation mode + the point attribute generated on a SOP previously

This is mostly a noob problem where i don't know how to format things

-> On the delay node for example i can use the $C variable but what is the expression or type of previous nodes to get my attribute in here ?

is this what you want !?! :?

I just made a custom attribute (JKC) for a simple sphere , then I passed this data to the CHOP and I shifted and stretched over time them via CHOP , finally I used Point SOP for converting $JKC to Color for visualization in the viewport 8)

hi,
thank you very much but it's not what i'm after.

Based on your previous example for example how can i drive ‘tx ty tz’ by ‘r’, for example the more is red the more a wave or a timeshift etc occurs…

i'm trying to rebuild a setup i've on softimage where i'm animating proceduraly polygon island independantly on a single geometry

On soft:
1. tag the point by connectivity with an ID, each pieces of geo get an ID
2. use that ID to generate a side particle/point system
3. add an attribute to tag the point by a sort X or radial, or Y etc then use this to modulate the animation on each pieces
4. animate that points
5. get back the point transform to the geo

i've done 1 2 & 5

about 3 & 4. where i do can animate the point but i don't know for example how to get a shop to combine the custom sort attribute to manipulate the animation.


can i do that in CHOP ?
or do i have to take the VOP route ?

I used same method in too many projects in Houdini , exactly like you I add a unique ID to each piece , then add centred point to each piece with same ID , Moving points , then put each piece to it's animated point (with same ID) .

But for doing that you don't need to CHOPs , you can do that in VOP SOP or Copy SOP , of course Copy SOP method is so slow , But VOP method is perfectly fast.

I'll make a simple example about this for you , Just wait a minute :wink:

What's your meant about using SHOP for controlling animation !?

for example using a texture file for controlling an animation ?

It's a simple example about this , I use Old-POP Network for animating points , But you can use another methods such as Dynamics.

Also in this example I just use position of the points for each pieces , But you can use this VOP method for Rotation , Scale and every custom Attribute too 8)

thanks i look at your file now,

by the way, here is my version where i'm stucked, using vop is tempting but doesn't allow the cool effect availables width chop right ?

From now i drive the animation based on $C but it's just too limitating, i would like to use my custom attrib “partID”

VOP is not for animating point's , it's for put each piece on it's own centered point with partID , you can use CHOPs for animating points , then use VOP for putting each piece on these points :arrow:

Also using VOP for putting pieces on the points is so faster than using for each SOP (foreach1 in your project) , I replaced my VOP SOP tool on foreach1 it in your project and I take this result :

Cook Time for ForEach method : 15.57 ms
Cook Time for VOP method : 1.06 ms !!!

Of course I set Number of Copy to 50 .

hey ! that's great for the cook speed ;-)

So, how can i drive a CHOP timeshift node for example by a custom attribute ? On my example file the “partID” attrib so the black one would be the last to be animated ??

i'm aware of the timeshift SHOP ;-)

ok this is where i am… in progress !
all is working, i have dealed with attributes in the CHOP and completed your VOP code to deal with the full matrix

the key was to reference the channel via chopct()… all these expressions each time different on each nodes, this is a little nightmare ;-)

anyway, here is my updated scene, how can i simplify my CHOP network please ?

for example can i simplify the transform part ???i can't find a way to use the transform node in place of the decomposed matrix… ?


So in the end of the day it is a working concept where i would like to deal only with a chop to have a more artistic control…

On Softimage i deal with things completely differently as i play with ICE and modulate the time by attributes to get procedural animation.

Is it practicable like that or do i need to test the VOP route like in ICE by playing with the time ? I don't know

hi,
How can i, using the VOP SOP deform technique from this thread, transform the normals too ?

For a small recap I use centered point for “mografing” letters with 2 supl attributes scale and N(for the rotations).

On the end i translate back the point transform to the geo transforming points.

This working great but one drawback is that the normal aren't transformed… and i can't get my head around the maths in the vopsop to rotate the normal.

does someone have a hint on this ;-) ?