Nvidia Flex collision problem

Hi all, I was playing on Vincent’ Nvidia Flex for TD. It’s wonderful!

I am trying to play with the colliders. I found there is collision plane chop, collision sphere chop and collision box chop options inside.
I am wondering if I wanna do a human figure collision by using a depth cam, what should I do here to pass the irregular shape collider to flex chop?

I used to succeed to realize it in Processing but have no idea how to do irregular shape collision with flex in TD. Anyone has ideas?

Thanks in advance!!


Anyone can help?


You will need to hack the code to import an irregular shape.

I believe in its current state, you can’t import an irregular shape.

Ok, I will have a look at the code. Thanks for your response! :stuck_out_tongue:

Is the collision Flex data a candidate fro TD to expose in the next COMP versions? It’s pretty cool, I would use it right away for my needs, P

I can definitely see a segway through Vincent Houze’s DistThresholdCHOP if there aren’t too many collisions. Unfortunately I went there for that issue a while ago and couldn’t get it to work for me. @vinz99 I cannot figure out where to put the .dll, it just keeps saying this:“Error: Faled to load the .dll”.
You can get away with CHOPs for a many-to-many distance threshold but you’ll hit performance issues at some point. For prototyping though it would be great. https://github.com/vinz9/DistThresholdCHOP/releases
On my part I have investigated TOPs and found a method but it’s still funky and needs more time. Gotta dedicate :slight_smile:
my 2 cents, P

Ideally, a shader juggernaut in the TD community (follow my eyes) can push a distance threshold shader working with TOP EXR input & output. That would just rock as a utility. I might be able to wrangle a budget for it actually. I was going to use it as a way to get me further than I am in shaders, that got me to look at compute shaders (by a few TD guys actually), but hen @malcolmbechard was explaining, compute shaders might be phased out because of Vulcan (I think I read that right). There’s also a good start by @3dwalker on his Geometry shader tutorials. Thinking out loud, cheers, P

Hey, so the dll goes either in a Plugins folder where the toe file is (just learned that recently, one day I’ll repackage the release zip file), or in a Plugins folder inside the Derivative folder in Documents.
See https://wiki.derivative.ca/Custom_Operators#Using_Custom_OPs_-_Plugin_Folder_Locations
There’s also a small tweak to make the lines appear with latest TD, see Distance Threshold Cplusplus CHOP (plexus-like effects)
For a cool GPU method without GLSL and without geometry shaders I highly recommend Paketa’s tutorial https://www.youtube.com/watch?v=0A01XKt_3rM
Otherwise pretty sure Malcom said geometry shaders were going to disappear with vulkan, not compute shaders.

that is strange - what is going to replace that? there are still a bunch of things where i cannot imagine the better solution, and actully Vulkan supports Geometry Shaders:

Hi @vinz99,

Thanks for the quick reply, and for correcting me about Geometry shaders being phased out.
Indeed, I have been speaking to @paketa12, and yes been following his tuts :clap: :clap: :raised_hands: :clap: :facepunch:, especially his new Plexus. I do have to give it a pretty substantial modification to do though, which we have been discussing: my point-cloud TOP is ~40-50 million points (divide into a few separate TOPS). The set of points that I am checking for proximity against these huge images is another point-cloud TOP but of approx 128x128. Paketa’s genius TOP work amazes me and I really like it, so I use it when possible including this case. But the Plexus tutorial matches 2 equally sized TOPS, which is actually a big diff for me, so I am expanding on that pipeline and also have been looking around for different solutions around this or around a part of it. P

Hi Stanislav, it’s a story between TD on Mac and TD on PC and shader support for both I think, can’t find the link anymore but it’s a discussion by @malcolmbechard & a few others. I love your Geometry shader tutorials, surely lots of the cool abstraction code you have in there will be re-usable I hope.

Hi @vinz99, one last question, I got your Flex version 4, put the .dll in the right spot, really nice, I might just use that instead of the regular. Still need some time to look into it. I have a very specific question for you that I don’t see out there:
getting collision hits per particle… maybe a position for example. That’s all I found:

It can be a massive amount of data I get that…
Just curious, all the best, P

I think, than I will need to have to change to other software, because no one other context or shader stages offers a possibility to change topology of geometry, and I intensively use geometry shaders in 90% of my work. for now there are a bunch of uncompatible things between Mac and PC, so for my personal point of view its a bad reason dont to use the most powerfull feathure just because of that. Really sad to hear Currently, because developing of TD constantly avoiding the topics of 3D in all sences, i just see that Unreal and co just slowly getting in front, so It would be really great to keep TouchDesigners 3D possibilies on most priority stage

Maybe this is not set in stone yet, sorry to bring that up since I am no expert in the TD roadmap.