Forums Houdini Indie and Apprentice generate circle of particles around hitpoint

generate circle of particles around hitpoint

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MCGrund
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Hey all,
I'm trying to generate a circle of particles around each of my collision points. This I got to work but what I can't get my head around is how to align these circles to the Hitnormals. I tried several things but my math is not the best and I couldn't find a solution. Can somebody please show me the correct approach?

Cheers

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particleRings.hipnc (271.1 KB)

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circusmonkey
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Hi,
took a brief look at your scene. You would be better off creating the circle of points in sops which could be copied onto the hittime point. Then in vop sop you could delete the points over time.

rob
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MCGrund
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Hey Rob,
thanks for the reply I'll try out your suggestion. I also found an approach to my problem over at odforce http://forums.odforce.net/topic/18365-normal-to-angle-how-to/ [forums.odforce.net]. I've attached my solution.

Cheers

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particleRings_02.hipnc (282.6 KB)

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circusmonkey
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You can indeed create a vector using the dot product method in a vop pop. My approach is always to try and keep things as simple as possible. The advantage with SOPs is there is no need to ever re-sim.

rob
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MCGrund
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You're of course right about that and I really appreciate the input.

I forgot to mention in my initial post that these circles are my starting point for a particle simulation. Therefore I'll have to do further simming down the road anyway.
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circusmonkey
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They maybe well be but keeping it in SOPs you will have more control ! . Use the points as a source Hunt my website out there you will find a ton of example files

Rob
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MCGrund
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Hey, I tried out your suggestion and yes… it seems like a much simpler and therefore better approach to me, too.
One further question though: Is it good practice to take the copied circles and feed them into a second Popnet like I did or would it have been better to feed them back into the original one. Coming from Maya the latter didn't seem like such a good workflow to me.

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particleRings_03.hipnc (294.8 KB)

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circusmonkey
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Hi,
Several points >

1) Your not writing anything out to disk ? After ever dop sim or pop sim etc. You should be writing the data out to disk.

2) You would take the data from the first dop > write it out , then use it elsewhere.

3) I am not sure why you are doing everything in one geometry node. That is a bad approach remember you can use as many nodes to like to manipulate and alter geometry.

Hope this helps
Rob
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MCGrund
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Yeah sure. Thanks for the hints!
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