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About bbentley81

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  1. Vellum Collision Problems

    FYI I got this working. the problem was with using a deforming volume based collision. Vellum seems to really want surface based collisions. My mothodology was off. I was trying to fix the sim,but I should have been fixing the collisions. Once penetrations and clipping was resolved everything worked great!
  2. Vellum Collision Problems

    Hello! I am trying to deepen my understansing of vellum by building the solver netowork myself. I have hit is very enfuriating sustuation were my character litterally walks out of her pants. When I use the sop based solver this dosn't happen. I am sure I am missing something but it seems most things I have tried are giving me the same result. I am using an almebic cache for the collider, and cloth geometry brought in from Marvelios Designer. I am using an collision source node to generate a vdb for collisions, and using a staticObject set to “Use Volume Collision” and “Volume Sample” for division Method. Here is what I am getting
  3. Help with multi solver

    Thank you for the quick response. This will be valuable information in the future. I got the problem worked out. I was making it harder then it needed to be. I used a popsource in the pre-solve input of a rigidbodysolver and every thing works fine. No need to chain solvers together to get the desired effect. Thanks again. Cheers!
  4. Help with multi solver

    Greeting all, I am trying to wrap my head around the multisover in dops. I have a sim of a plank breaking. I have upacked the sim and placed a debrissource node after. I then copy cubes onto these points and point a pop source to them. I have a packedrbd object running into the multi solver which runs a pop solver then a rigidbody solver. It kind of works but when the cubes hit the ground the shake and jitter and generally misbehave. Any Insite into why this could be happening would be greatly appreciated. I have attached a sample file. Cheers! B plank_troubleShooting_v04.hipnc
  5. generating constraint networks from impacts

    AMAZING!! Thank you so much!
  6. Greetings All, I am trying to generate constraint network geometry based on the impact points of packed rigid objects. I am a bit new to dops and I would like to know if my logic is correct, as well as ask a few questions. Logic: Within the sop solver node in dops there is a relationships import, an impacts import, and a dynamic objects import. I want to use the points generated by the impacts with a connect adjacent pieces sop to make the primitives for the constraint network. I will somehow have to get the name for the constraint anchors from the dynamics objects import for the points. Questions: Should this sop solver be attached to the post solve of the rigidbody solver, into a multi solver, or into the constraints network node? How can I get what point corresponds to what object. I am thinking maybe the primuv vex function as I am assuming that the points generated are on the surface of the impact do I need to make the impact point persistant, possibly with a geometry solver inside the sop solver 0_o. how do I point the constraint network to these new points and primitives. any help would be greatly appricitated. I have attached an example file with my bubblings. Cheers, B contraintsFromImpact.hipnc
  7. UV to mesh with matching prim area

    YAAAASSSS!! Thank you so much. This worked perfectly!! I've attached the working file for those few who are interested. matchAreaSqrt.hipnc
  8. Hello, I am working on a marvelous designer to Houdini pipeline and I have hit a snag that I am hoping someone could help me with. I am trying to take the draped model and flatten it to the uvs that come out of MD. This part I have working with a point wrangle with "@P = @uv;" The part I am having trouble with is matching the area. I have tried: 1. make a measure sop set to area on both the draped and flatted model 2. promote the area attribute to detail using sum to get the area for the entilre model 3 get a scale factor by drapeArea/uvArea 4. use this in a point wrangle to scale the @P by the scale factor. float currScale = detail(0, "area", 0); float targetScale = detail(1, "area",0); float scaleFactor = targetScale/currScale; @P *= scaleFactor/1000; This, however, is not working. I am not sure if it is a problem with my math or my logic. If anyone can shed some light on this I would be greatly appreciative. I have attached an example hipnc file for reference. Cheers, B matchArea.hipnc
  9. How to emit dop objects?

    YES!!!! Thank you so much. This is exactly what I was looking for!!
  10. Hair Shader Tips

    This looks like a good start to me. How did you get the braid to work? I've been looking for how to do that in Houdini for some time now. I also find it is hard to judge how "real" something looks out of context. Maybey a test on a model head would give better feedback on what direction to push the look. I know it's not a technical answer, but I think it's a good place to start. Great work!
  11. How to emit dop objects?

    This is great! I love that site. It is like the unofficial bible for getting a deeper understanding of Houdini. I have done a little more digging into this and it seems that each type of DOP object needs to be treated differently. Which in hind site make sense. Currently, I am looking at the Grain solver, specifically the solid grain object. I know I can make copies of the solid object in dops by putting an expression in the creation frame I think. What I am stuck on is, How do I make copies of the geometry that the grains should deform and then deform them with the pointDeform sop? And again I am going back to that great bacon stacking sim they showed when they first added grains to the toolset. it can be seen here: at 00:37 So many questions!!! Thanks again. Cheers, B
  12. Greetings all, I am trying to figure out how to emit dynamic objects like particles. An example would be if I wanted to do a shell casing simulation, or something like in "Cloudy with a Chance of Meatballs" when bead (fem or grain solid object) could be emitted from a plane in the sky. I think this is what they are doing in the bacon example in the grains masterclass, but that file is not provided in the course materials. I have been toying with dops for a bit but I don't even know where to start with this. Would I use a multi solver? Any help would be appreciated. Cheers, B
  13. Hello, I am diving into the hair and fur system in Houdini 16.5. It is really amazing how intuitive the new system is. I have some questions; 1. I want to be able to change the bending stiffness along the length of the guide curve. Is there a default way to do this or will I have to unlock the "animate guides" node and add a ramp on the @kangular attribute or something to do this? I assume the u value of each curve is being generated somehow because of the color display. 2. I did a test sim with very few guides just to test the workflow. Before I rendered the hair I did a file cache of the generated hair so it is reading from the disc and not calculating from the simulated guides. Is this the correct workflow. 3. In my render, I am seeing some of my generated hair popping back and forth. Is this because I used so few guide curves? 4. I am looking for a way to make curled guides. There is a great article in 3D world issue 218 were the artists makes an HDA that will spiral around an arbitrary curve but he doesn't go into detail about how it works. I would love to build something like this myself but I am not sure where to start. Any pointers or resources would be awesome. Thank you in advance for the help. Cheers, Bryan Bentley
  14. Constraints for FEM objects

    Greetings, I am working on a project was I need to have fem objects stick to a collision object 0_O. I am a little lost on how to accomplish this. There is a great section dynamics constraints with wires here http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#wire_solver_and_dynamic_constraint_networks_.28sticky_wires.29 But I am not sure if there is an equivalent for FEM. Any help would be greatly appreciated. Cheers, Bryan Bentley
  15. Greetings, I am rather new to chops in Houdini and I am absolutely baffled by them. I was hoping some of you kind souls could lend a hand. Questions; 1. What is the difference in usage of the "fetch" and "channel" nodes? They both seem to pull parameter data from other parts of the scene. When would you use one over the other? 2. How does one just take single channel from a chopnet and drive a parameter? I have used the motion effects menu and you get this strange "Overridden by /obj/geo1/motionfx/disable_export1 twist2:strength" which seems very non-Houdini like. It feels like it is hiding something. 3. How does one use the chop expression? There is not much documentation on this, like what are the arguments you need to feed it, and what does it return. Furthermore, in the docs, it has been replaced by hou.chopnode but I cannot find use for that in the context of the larger system either. Possibly the export chop? I am sure there are reasons for all these things, and I am still rather new to Houdini so any help would be greatly appreciated Cheers, B