archo_p

awesome, just what i was looking for! Thanks konstantin!

I have been needing to make some custom utility UV sets for use in things like Unreal nDisplay and other technical usages of texture coordinates. I am using some atypical techniques to create and convert P and other attributes from second inputs on attribute wrangles and such, all is fine for this, but viewing the UVs has been tricky. What I'm wondering is if there is a way to get a vector attribute to be "tagged" with the Tex "sub-type" so that it is available in the UV Viewport auto attribute list. For now I've had to always create my UV attributes with a UV Texture SOP and then set those attributes to my results in a wrangle so that they maintain this mysterious (Tex) signifier you can see when getting info on a node next to the attribute ( for example : "uv0 3flt(Tex)" ). I'm just wondering if there's a way to add this "tag" to an attribute down the pipe instead of via a UV SOP that initializes the attribute, thus making it appear in my list of uv attributes in the UV Viewport. I can't discern an option for this in attribute create or otherwise, nor can i find an official name for this attribute "tag" or "sub-type", anyone know? Thanks! P

Thank you @anim now i see the network path and dive target field in Type Properties and did figure out putting if($F == 1, 1, 0) into the Impulse Activation parameter of POP Source to get one blast of particles. I'm coming from TouchDesigner land, which doesn't have nearly as complex a way of doing external assets, so getting used to plethora of options and methods!

Cool thanks so much Noobini! The step by step is great and worked. That makes sense then to think more about volumes for collisions for the grains. I'm still quite confused about how unlocking that vellum solver turns it into a completely different network from what was in there previous to unlocking, the collision behavior and null that were in there are completely gone after that move, i get how there might be hidden nodes, but totally don't get how unlocking the node seems to "remove" the popcollisionbehavior and force_output null, and re-matching the definition brings them back. curious I guess I need to find a more thorough description of how dynamics in general work because it seems so unintuituitive compared to other workflows in houdini ( sops, cops, etc) but i bet if I just got a real rundown I could be better equipped to experiment, anyone know of a good place to start? Just seems like there are so many different ways to setup DOPs. As well I'm still interested in finding a way to just have a fixed number of simple POP particles, so will continue hunting there. Thanks again! p

Total noob to dynamics in Houdini. I've been trying to wrap my head around Vellum as it seems designed for this need ( fixed number of dynamic elements ) but I really just want a particle system that starts with a fixed number of particles, no birth, no death, use forces with turbulence to get them to a collider and use the Stop collision behavior to stop them in their tracks upon collision. I can do this with a simple emitting POP setup, but i need a fixed number of particles. Vellum grains seems overly heavy for what I need ( don't care about per particle interaction right now) and I can't for the life of me find any good example of getting vellum grains to have their stopped attribute set to 1 ( POP collision detect doesn't seem to effect them?). So primarily I'd love to just see how to setup a fixed number of POP particles, but as well wouldn't mind being shown how one could stop vellum grains from getting dynamics applied after hitting a collider. Finally, in either case, how or can you specify one collider that allows a bounce, while another has a stop behavior. In general I just haven't really gotten my head around DOPs so trying to understand. For now just attaching my basic emitted particles that get stopped by using a POP collision detect. Thank you! P stoppingParticles.hiplc

Thanks @anim! This is poly bridge/ray solution is exactly the kind of thing i was looking for, thank you! @konstantin your example is very intriguing, will need to investigate that further to see what is going on there and how it might be of use. Thank you for your help, this is great!

Hello! Relatively new to houdini modelling. I have some old experience with nurbs modelling from old Rhino days and have been using poly and boolean to some success, but when i'm making inherently 'nurbsy' forms I find it difficult to get back to clean polygons that have good topology preocedurally. I think there is a simple solution here I am missing so just hoping for some best practices from the masters! I have a trimmed nurbs surface that I want to get back to polys by skinning the profiles but with cross sections generated along the surface of the source nurbs surface. Since its trimmed the UV curves of the nurbs aren't super useful. My hope is to somehow get projected cross sections, convert and re-sample so they have the same number of points and use those as cross sections in a skin sop that takes the re-sampled trim profiles as U boundaries. Any help or advice about how to approach would be much appreciated. I am attaching a simple file with a null representing the shape I am hoping for called "idealShape_for_cleanpolys" and then a part of the network where I am crudely converting the profiles to polys for a skin operation, but obviously this has no U sections so is just a simple skin between the two profiles with no V information between the two profiles. Cheers P trimmedNurbsToCleanPoly.hiplc