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JeffBenjamin

chop export node only exporting one channel

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This is the first time i've worked with chops, and i'm trying to figure out why my export node is only exporting one channel. I've got a cloth object rotated 45 degrees and 10 units above a ground plane, and let the cloth fall to the ground. The cloth keeps penetrating the ground plane and never quite settles down, so I use a geometry chop to import the positional data and basically apply a low pass filter to remove the jitter. Everything looks fine in chops, but once I export that data back to SOPs the cloth object is no longer at a 45 degree angle (it's parallel to the ground plane). I think I have narrowed the problem down to the fact that the export node is only exporting one channel to all points, instead of one channel per point. I have played around with it for a few hours but can't seem to get it to work. Would someone mind taking a peek at this hip file and explain what I'm missing? Thanks in advance!

cloth_test.hipnc

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The export is for channels and not points. You have to use a Channel SOP to apply the data back onto each point.

Cheers!

steven

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The export is for channels and not points. You have to use a Channel SOP to apply the data back onto each point.

Cheers!

steven

Thanks Stephen, I added a point sop and then a channel sop which did the trick. I am still a bit confused as to why my original method didn't work properly, and I think it is based on my understanding of the definition of the word 'channel'. The export node says that it ' allows you to match a CHOP

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It is, but the Point SOP will only evaluate the parameter at the current frame. This means that all points will use the same value from CHOPs, which is not what you want. What you want is to have each point use a different frame from CHOPs.

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Hi,

The difference is you're reading geometry data & not channel data. For example, channel data refers to the transform of an object, animation curves etc. Geometry data usually refers to point position & attributes.

I agree the definition of "channels" is ambiguous but after you read through the help for the channel editor & CHOPs, it should be clearer. I hope. ;)

Cheers!

steven

PS: You don't need a Point SOP before the Channel SOP.

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