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About DeeLan

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    Dylan Smith
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  1. I'm having a play with grains for making simple ropes and cables, and the problem I'm having is that they just bounce and stretch waaaaaaaaay to much! The rest length attribute on each prim is the exact length of those prims (and therefore the sum of all the rest lengths is the length of the rope) and the substeps on the pop solver are set to 10. What I want to do is simply reduce the amount that the rope stretches and bounces. Up till now, the only real solution I've found (and seen other people do), is mess around with forces and substeps (in one case I turned them up to 1000), but doing it that way just feels so convoluted and still doesn't let me tune in the exact results that I want. I've also been playing around with attributes as well as having a dig around in the solver itself to see if there is anyway to modify it, but alas I have come up with nothing (I'm struggling to figure out whats going on the grains node). I guess what I'm wanting to do is find a way to control how the rope moves/looks (ie the stretching and bounciness) with physical properties instead of forces. In other words, instead of having to use a pop drags and all that, just get the rope to not be so susceptible to stretching in the first place. Does anyone have any ideas?
  2. Is AMD potentially risky? (Threadripper)

    Please correct me if I'm wrong (there's a lot of great info in this thread, but after a while I was finding it a bit difficult to keep track of the results), but compared to each other, the TR 1950x really excels in some areas (such as Pyro and Mantra), but falls a bit flat in others, whereas the i9 1900x perhaps just OK across the board. Also, both CPUs have issues that could cause problems with long sims and renders (temps on the i9, NUMA and Performance Boost weirdness on the TR). Am I correct with this understanding? Has anyone here tried the TR 1920x yet? I was looking at some articles from Puget Systems (I'll link them below) and it seems to perform close to (sometimes on par with) the i9 1900x. So I was thinking It might potentially be an alternative for the 7900x that could save us a few bucks ($200 here in Aus). Also speaking of Puget Systems, I sent them a request for some Houdini tests. I don't know if they'll actually do it, but it can't hurt to pop them an email asking for it if you want to see it (after all, the more that ask the higher our chances). https://www.pugetsystems.com/labs/articles/V-Ray-CPU-Comparison-New-14-16-and-18-core-Skylake-X-Processors-1043/ https://www.pugetsystems.com/labs/articles/Cinema-4D-CPU-Rendering-Comparison-New-14-16-and-18-core-Skylake-X-Processors-1038/ https://www.pugetsystems.com/labs/articles/Arnold-for-Maya-CPU-Comparison-New-14-16-and-18-core-Skylake-X-Processors-1045/#Conclusion
  3. I'm trying to get FLIP and Rigid Bodies to interact with each other. At the moment I've been dropping RBDs (both whole and fractured objects. No packed geo) into a deep tube of water and trying to get them to slow to a stop before floating back up to the surface. So far the best I've been able to do is get the rigids to collide with and move the water. The water has absolutely no effect on the rigids, and neither of the object's masses seems to have any effect on the sim either. I've also tried increasing the Feedback Scale on the FLIP solver (the most common suggestion), plugging the FLIP solver into the merge node before the RBD Solver, and changing it from "Left Affects Right" to "Mutual" (both these changes gave extremely explosive/unstable sims, and still didn't work), changing the rigid solver from bullet to RBD, and playing around with the various collision and velocity settings on the FLIP solver. Nothing worked at all. Does anyone have any suggestions of how to get FLIP and RBDs to play together nicely?
  4. [SOLVED]Shape Made Of Even Quads?

    Hey Atom. I would usually do something like this in maya, but I did have a crack at doing it in Houdini. It uses curves to define the shape instead of a boolean. You still get ngons and tris around the borders of the shape, but theres not of that weirdness in the center. Its a bit janky (only had about 10 minutes to do it), but with a bit of love (and maybe some VEX) I'm sure it can be cleaned up into something workable even_quads_v1.hipnc
  5. So it turns out that the issue was I didn't realise that DOPs actually shares data between different paths of execution (not sure what the actual name was), and that merges share the data left to right. because of that the spawner particles were completely gone by the second frame which gave me the messed up results. Its all fixed now though. POPs_stream_problem_FIXED.hipnc
  6. So I think my issue may be with how streams work (still figuring it out). I've been trying to read and write the value of the stream attribute using @group_streamname but it won't allow me to do that. I understand not being able to modify the attribute, but why wouldn't it let me read it?
  7. I'm currently following along with Rohan Dalvi's Motion Graphics tutorial, and I've run into two issues with the particles from the outer ring that I thought would have simple solutions, but so far have completely stumped me. The first thing I've found is that each point would spawn two particles, resulting in two lines very close together, and I want to get only one particle/line for each spawn. I've figured out the reason for this happen is that in my POP network I do two separate replicates, each on a different particle stream/group (so that I can have differing life lengths), and the replicate POP passes through the original particles (even those no being replicated) so after merging the replicates back together, I end up with two separate sets of the original spawner particles. Now the solution I came up with was to remove the points I didn't want to replicate, do the replicate for each group, then merge them back together (exactly like I would if I had this issue in SOPs). Problem is though that didn't work at all. I tried both Kill POPs and POP Wrangles, and a few different setups but nothing worked. I've included some notes with the scene file to give better explanations. Secondly, when the spawner particle collides with the tube, the replicator keeps replicating it, so we end up with a bunch of points stacked on top of each other, which I don't want. My idea to fix was to have a node placed straight after the replicate that removes any particles in the "hitparticle" group from the "stream_General_Spawner" group. That way, on the next frame, all the collided particles won't be replicate again. But this didn't entirely work either. "Combine Groups" on the Group POP almost did the trick, but in addition to removing the particles from the spawner group, it also removed them from the hitparticle group, which I don't want because I have a wrangle that does stuff with that group. Does anyone know why these issues exist? I'm guess that I'm missing some sort of foundational knowledge on how POPs work? Any recommendations for tutorials or articles to go along with the documentation to help with this? POPs_problem.hipnc
  8. Map the audio spectrum onto a geometry

    That's Perfect! Thanks Mate!
  9. Map the audio spectrum onto a geometry

    Please correct me if I'm wrong but "Sample Rate" and "Channel Length" are "Samples/Sec" and "Length Samples" respectively (as seen when middle mousing the spectrum node) right? Also, any suggestions how we would use this to map the magnitude of the frequency onto geometry? 'chopci' expression and a point attribute? (I'm a complete CHOPS noob, so I'm struggling with this a fair bit).
  10. Post-Voronoi Boolean Problem

    I've stumbled across a rather annoying little issue. As you can see in the attached scene, If I perform a subtractive boolean operation after a voronoi fracture, things get super messed up. The two major issues being that a bunch of pieces are randomly missing faces and the new faces generated by the boolean are not connected to their respective pieces. I managed to get things working (albeit marginally slower) by utilizing a for each loop. Does anyone know what might be the cause of this issue? Has anyone run into it themselves? post_voronoi_boolean_problem.hipnc
  11. Quick question. How does one modify Constraint Attributes using a SOP Solver. In my example scene, I'm trying to divide the 'angle' attribute by 2, but it isn't having any effect in the scene. Oddly enough, the geometry spreadsheet recognizes the division when viewed within the SOP solver (named 'DIVIDE ANGLE') itself, but when back in the DOPs context its as if the SOP Solver was never there. Modify_Constraint_Values_01.hipnc
  12. Hey guys. I'm trying to figure out a destruction setup for things like fences, wooden frames, plywood walls (that thin stuff thats really easy to put a hole in accidentally) etc. The part I'm stuck on at the moment is how to mimic things that are nailed together. Specifically, how to set it up so that when the fence/frame/whatever is hit by something, it doesn't just break apart, but instead just becomes a slight bit loosened, causing it to wobble a bit and fall over slightly. I realize that explanation probably makes little to no sense, so I've included two reference images. One depicts the effect that would happen for an entire fence, the other is for a single beam. I've got an example scene that uses the Cone Twist Constraint. It it gets me part way there, but is obviously way to static, and just stops suddenly. What I would like would be some subtle wobbling, as well as the beam the rotate down abit (to mimic the photo with the horse). I had the idea of using a Glue constraint with a bit of stretch. Problem is, I have no idea how to get a glue constraint to stretch (or if its even possible) and I couldn't find anything on Google about it either . Is anyone able to point me in the right direction for figuring this out? I'm still struggling to understand constraints so any guidance would be extremely helpful Nailed_Wood.hipnc
  13. Hey Guys, I've got a really annoying problem with RBDs at the moment. I've attached a scene for reference (It may take a little long to load as all the caching is disabled. Also sorry if it looks weird. I've been playing around with keep everything from fracturing to simulation in the one network. Everything we need to work with is right at the bottom in the Yellow backdrop.). So I've got a setup with packed prims and glue constraints (which as far as I can tell is fairly standard). If all my pieces have their "Active" attribute set to 1, everything works as expected. However, if I set some of to have an 'active' attribute of 0 (I've done this in a weird way earlier in the node tree, but I've tried this with multiple different methods and they all yield the same result), nothing moves until either an object collides with it, or I start deleting the glue constraints, and even then I can get some weird results if the glue strength is 0. To illustrate this, I've given my constraints a strength value of 0. What if expect is that all the active pieces will fall straight down, and the inactive pieces will stay where they are. However, if you hit play, nothing moves. If you jump into the dopnet "RBD SIMULATION", and then disable the 'constraint network' dop, then it acts exactly as I expect it to (considering that there is no strength in the glue). Alternatively, leaving the 'constraint network' dop enabled, and also enabling the "ALL ACTIVE" sop (colored blue), then it also acts you would expected for a network where every piece is active. I don't understand why, but having even one piece with 'active' set to zero, and a constraint network attached, effectively yields the result as if everything was disabled. I'm just confused because it doesn't seem to be acting the way I think it should. Is this a case of "thats just how it is" or have I set my network up wrong? Controlling_Fractures_Problem.hipnc
  14. Help with Constraints

    Thanks mate that really helps!
  15. Help with Constraints

    Hey guys, I have two quick questions. I'm trying to learn how to make constraint networks by hand. I've noticed that for some reason, when I define the strength of my constraint in sops using a wrangle sop, I only need relatively low values. However, if I delete strength attribute from my wrangle sop and control the strength in dops using the 'Glue Constraint Relationship" dop, the values needed to achieve the same effect suddenly become massive. For example, when I define the strength in sops, I only need a value of 10 to get the effect I want. However, controlling the strength in dops (no strength attribute defined in sops) require a strength of 100,000 to achieve the same outcome. I'm wondering why there is this massive difference between sops and dops. Also, say I wanted to add a second fracture object to the sim (unique the first one), with a constraint network of its own, whats the best way to go about bringing the second constraint network. From my understanding, adding a new object is as simple as adding a second RBD Packed Object dop, merging that with the original, and plugging the merge into the rbd solver. But with constraints it seems I would need a new constraint network dop and a new glue constraint relationship dop for every set of constraints. I'm just wondering if there a way to do it all through one constraint network dop and use multiple glue constraint relationship dops, similar to plugging multiple RBD objects into one RBD solver. constraints.hipnc