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Everything posted by catchyid

  1. what makes rbd material fracture time dependent?

    I think something is off in my setup, I tested the node on a box and it is NOT time dependent Edit: just restarting houdini fixed the problem!
  2. hi, Houdini 17.5 I am using rbd material fracture and even thought the input mesh is static , the rbd material fracture is time dependent, i.e. it re-fractures the mesh on each frame (same result!)? could not find any time expressions on the node parameters?! any hints? Tx
  3. pyro explosion sim question

    Hi, I've looked @ couple references, and explosions start from nothing (i.e. no smoke, fire) and in one frame there is a big fireball, smoke, and debris/projectiles (plz see attache ref images). My question: how in one frame it's possible to have all these elements (organic smoke and debris)? I have some ideas: a- for pyro sim --> add preproll velocity to pyro sim - not sure if will get organic smoke shapes? sub-stepping is a bad idea in my opinion, it will slow sims lot? b- for projectiles/debris --> can trail their motion, emit from the trail, but the evolution of the smoke might not look right Tx for any suggestions
  4. How to create a pyramid from a point an a grid?

    Thanks Konstantin Also, it's possible to use convexhull node and it will give the same result...thx again
  5. Hi, I am given a base (could be a quad or triangle) and a point , the goal is to use the base and the point to create a pyramid (plz see image or file). One idea I have now is to extrude the base in the direction of the point the scale to zero the extruded surface (then fuse to merge points), other ideas? Note: I don't want to use vex or python here Tx createPolygon.hip
  6. hmmm...wondering how come I did not see that Maybe I was super tired that day ! Thaaaaaaaaaank you
  7. Hi, I want to scatter points on a surface with a specific point separation? If use "pointsfromvolume" node it fills the entire volume of the surface, and "scatter" node does not have this "point separation" property. Is there a way to do that? Note: I need to have "point separation" property because I want to use "Pyro Source" which requires this number (plz see attached) Tx pointsVolumeOnSurface.hip
  8. How to generate "contour" lines

    Hi, (plz see attached image). I am not sure if these are contour lines or if they can be described procedurally? My goal is to use them to create velocity fields around that character. Note: I don't really care if they rotate clockwise or counter-clockwise, as long as the circles are around the arms cross section, legs cross section...One idea I got now is to use the underlying mesh edges (select whatever I wand and delete the rest!?), are there better ideas that can be applied on any mesh? Tx
  9. gradual point deform control?

    Hi, I have a curve that I need to deform with a mesh, however , I am only interested to deform a part of the curve that is near the deforming mesh. Question 1: I've changed deform "Radius" to small numbers (to make sure that far curve points are not affected by the deforming mesh), yet the whole curve gets deformed with the mesh, is this normal? Question 2: Is is possible and easy to paint weights on the curve to gradually deform them? Note: I've tried to use point deform "capture" mode first, and I got two parameters: weights and point indices (and all curve points are captured no matter how far they are), however editing these values does not seem straight forward As a final resort, I selected the curve points to be deformed (see attached), however there is no gradual transition and it looks bad (possible to fix with smooth, but not the most straightforward way) Thx t.mov
  10. gradual point deform control?

    Thank you Aizatulin
  11. hi, I have a digital asset that has menu A and menu B --> I use "Menu Script" to generate dynamically the contents of each menu, however I have this dependency : Menu B contents depend on A (so if user changes menu A selection, menu B needs to dynamically regenerate itself). Currently the only way to "refresh" menu B when A is changed is to manually select Menu B which calls its "Menu Script" (counter-intuitive for end user!). So my question : is there a way to force Menu B to run its "Menu Script" when Menu A is changed?
  12. lava flow question

    hi, i need to fill a street with lava that is moving in one direction (plz see attached). To make the lava flow across the road and given the street is level, how should I do that? One solution is to adjust particles velocity in each frame (i.e. blend v such that on each frame 10% desired velocity, 90% existing velocity), would that work? if not, any other idea? I thought making the floor inclined or changing the gravity direction, but that would cause possible issues .... thx
  13. lava flow question

    WOW, thaaaaaaaaaaanks everyone and special thanks Jesper
  14. lava flow question

    Thx Atom Yup, I was able to generate the sim easily as you mentioned, thx a lot. We are using an external renderer, so we develop the shader ourselves. I would need to enable rest/rest2 to get UVs on the Lava, right? If there is an article or a tutorial that discusses the general concept plz share it thx again
  15. lava flow question

    Thx My question here is : is there any other way to generate an initial (e.g. one frame only) convincing lava flow shape other than simming a heavy viscous fluid for so many frames? I am talking only about the first frame? this way each shot can have its own preroll and just sim for couple frames for that shot. Thank you ...
  16. lava flow question

    Another question regarding Lava, in the attached image below, the volume shape of the fluid indicates its high viscosity. Now my question: I have a large pool of Lava with many shots, and each shot is like 1 or 2 seconds, if I want to produce these viscous shapes, then I need to have super long preroll to make the sim naturally produce this viscous shapes per shot...Is this is the right way to go? Are there any cheats where I can give this viscous volume illusion without simming for so many frames? Thx
  17. lava flow question

    also a force node would work good here .... thx
  18. Hi, I am using Script solver inside a DOP RBD bullet sim, I was able to change velocities of individual RBD packed objects, however I don't know how to access/modify constraints network parameters (e.g strength, add/remove broken group, etc.)? The constraint network in defined globally "Relationships" subdata (i.e. not attached to each object), below is the code I am trying to write : from __future__ import with_statement def solveForObjects( solver_data, new_dop_objects, existing_dop_objects, time, timestep): dopsim = solver_data.simulation() relationships = dopsim.findRelationship("constraintnetwork1") constraintsnetwork = relationships.findSubData("constraintnetwork") # geometry lives inside 'constraintnetwork' subdata geo = constraintsnetwork.findSubData("Geometry") #that works, but it's not a hou.Geometry that can be edited! with constraintsnetwork.editableGeometry() as geo: #error: AttributeError: 'DopData' object has no attribute 'editableGeometry #.... do something here
  19. vex pretanslate question

    Hi, assuming: //xform is 4x4 matix //pivot is a 3D point then does pretranslate(xform, pivot) mean logically : move to -pivot, rotate, then move to +pivot, in terms of eq, should be look like this: Tr(-pivot) * xform * Tr(pivot), where Tr is a translation matrix? Thx
  20. Robust solution for RBD Fracture???

    just an update : I've tested all possible ideas mentioned above, it's seems to me a bug in the tool itself (or at least the implementation is not robust enough)...I could not find a bullet-proof solution, for each pieces, i've tried different methods (different seeds, different number of fraction points, always break per piece, pre-cut mesh with boolean fracture using simple planes, etc)...it worked finally for most pieces but again, it's a random process...
  21. Robust solution for RBD Fracture???

    Houdini 17.5 Hi, I am using RBD material fracture to break a building (it breaks floor by floor, elements by elements, so it would be a simple as possible to the fracture node!), however when I turn on "Edge Details", I get the cutting planes in the output geometry!! I've tried to play with attributes like Noise Height/Size, however it's like a random process, one keep trying until "some" values will work. My question: Is there any solid/robust solution to add details to RBD pieces?
  22. Hi, I have bullet sim, have static object, am connecting it to static solver...is there any use for adding this static solver? either way, the static object will collide with other dynamic objects? thx
  23. How to force a hython script to run

    an update if someone is having the same issue --> hou.time() makes code frame dependent so it will cook on each frame (even no input has changed) which fixes the problem
  24. Hi, I am loading assets using a python script node (see image). The assets are being cached on the farm and the first time the script runs, most probably, the cache would be empty hence the python code loads nothing (makes sense), after a while the cache gets created, HOWEVER, the script python node does not re-run and gives the previous cached result (which is empty cache) --> so, to force manual reevaluation of the code, I just go inside the script, add a space or do any modification and rerun the code and the now the cache gets loaded! Any ideas how to designate that this python script should be always run and not use the previous cached result? I am also open for a better approach if it exists cheers
  25. Hi, Is it possible in hython to load content of xyz.bgo.sc into houdini without using 'file' node? I need to load many geometry files to process them, I know i can use SOP for-loop with 'file' node and merge result, but I am wondering if it's possible to do that completely in hython? Thx