Converting Sops to Chops using Laser Chop missing Z-values


I’m working on a project that processes SOP geometry in CHOPs using the Laser CHOP before re-converting back to SOPs using the Limit SOP.

The Laser CHOP, however, only grabs X and Y values when converting from SOPs. What should I do grab the Z-values of my geometry?

Below is the project file detailing this process:
SOPs :arrow_forward: Laser CHOP :arrow_forward: Limit SOP :arrow_forward: Rendering

SOPs to CHOPs to SOPs again.toe (13.4 KB)


To clarify, the limitation of not having z-axis values is that I can’t rotate or my camera since the output is essentially flat.

my hacky workaround is to rotate the geo by 90 in y-axis, convert to CHOPs via laser and then rename the X-axis to Z and merge with the original data-stream. That said, the results are still distorted.

SOPs to CHOPs to SOPs again_zaxis hack.toe (16.6 KB)

I would suggest not using the output of Laser CHOP.
Just work in SOPs format throughout, only sending the final geometry to the Laser CHOP.
If you do need to work with the geometry as channels, use a SOP To CHOP to convert it.


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hi @rob

Why would you recommend against using the Laser CHOP? Is there a more efficient way to go about parsing SOP info?

I find the pulsating rhythm of the Laser CHOP really pleasing and enjoy playing with the step size parameter. Here’s some quick documentation of the sort of animations I’m making using the CHOP conversion process.

In the below example, I’m merging the z-axis channel from a SOP to CHOP with the X and Y channels from the Laser CHOP. As you can see, even though I’ve tried to resample them at the same rate, the channels seem to be out-of-sync.

Combining Laser and Sop to Chop.toe (13.9 KB)

Is there a way I could replicate the speed and step size controls of the Laser CHOP with the SOP to CHOP? Or maybe if you could explain to me the difference between how they operate, I’d understand why I shouldn’t use the Laser CHOP.

Thanks very much!

The Laser CHOP will convert just the X,Y components of the geometry, while adding laser-specific repeat points, queuing and stepping etc.
You could try using the Resample SOP on the original geometry to get similar stepping effects, before feeding the final result to the Laser CHOP.
Or convert the SOPs with the SOPto CHOP, and use a Resample CHOP on that.
There are lots of different options, which may give different visual effects, but the only take away is that the Laser CHOP conversion itself, discards the Z channel and has its own queueing mechanism.


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Got it, got it. Thank you!