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Found 105 results

  1. Hi, I just want to do it for experimentation. What's the best way to break up the edges of a pyro sim post sim with or without rest fields, and avoid swimming noise? If I have dual rest fields, do you combine them using a Mix node where the connections are rest, rest2 fields and rest2_ratio as the bias? Because there is also rest_ratio attribute. After this, do you displace the density volume using velocity field, gradient of the density or gradient of the SDF converted from density? Also negate the direction? I read here some people advising to use gradient or velocity to the position of the noise for example. Lastly which noise is more suitable for this task? Thanks a lot
  2. Hello, I'm trying to use voronoifracture node and found that it's different from the previous version(H16.5). So I imported to H17 from my old project made with H16.5 and now I have two different SOP named same. Is there any way to create the old voronifracture node in H17? One on the left side is new voronoifracture node in H17, and the right one is imported from my project made with H16.5. Thanks in advance!
  3. Hi everyone, I'm trying to make each connected points(@class) being deleted overtime when they above XZ plan. I made a bounding sphere for each @class and copy to itself with decreasing @pscale when it's above the plan. And delete the points outside the sphere. It works well when I set it to "single pass" but it works totally wrong when merges all iterations together... I have attached an example file below, it'll be fantastic if someone can help me out with this. sopsolver_in_loop.hip
  4. Hi, I have several meshes and a point and I would like to find primitives/points, the normals of which are directed to that point. To make it so I want to get vectors (and store them as an attribute) from that point to each of the points of these meshes and then compare them to its normals. But the first part doesn't work as I expected, what am I doing wrong? Or should it be done in a different way? facing_to_q.hipnc
  5. Hi folks, I recently saw this great tutorial from Entagma: http://www.entagma.com/houdini-17-quicktip-packing-geometry-using-the-uv-layout-sop/ It uses the UV layout SOP to pack geometry. My question is: How would I modify this technique to pack seperate words, as opposed to individual letters? Any pointers greatly appreciated!
  6. magnet force on two directions

    hello! I am having trouble making gravity work in two directions. Basically the world is a tube and I want objects to magnet/have a gravity like force along the Z and Y axis but not on the X axis. I attached my hip file and a picture. Any help would be great! Thank you! tube_attractor.hip
  7. Good day everyone! I been stuck for a while with a simple task, such as to move all of primitives, which has attribute "class" (cause primitives separated from each other threw "connectivity" node for later use as pseudo group) to World Coordinates XYZ = 0, 0, 0. Does anybody know how to solve that? Especially helpfull will be solution threw SOP nodes or VOP nodes. VEX welcome as usual, but can this problem be solved without scripting by the same time? Thanks
  8. Hi, This is giving me headaches for two hours now.I know it would be much easier in vex,however I dont know how to achieve this effect. If anyone can please point me in the right direction that would be greatly appreciated! There are some arrows shoot into ground in this scene,I want to make some small crushed stones in the first catch point. But the question is how i can get the one primitive source in just one frame? Transfer color is the best way i can think whitin my all power. Let me show you some GIF shot204.hip
  9. Hi. I am trying to figure out the usage of the Basis SOP. The documentation and web searching hasn't given a clear answer. All I understand is that this node is intended to modify NURBS. But parameters tweaking don't give me a distinct effect on a geometry so I am slightly confused. How does it work and what is the usage for the Basis node?
  10. Hi, I am currently creating a simulation with flip fluids that are affected by a vortex force. I need the velocity/lift attributes to be animated independently throughout the simulation, though no matter how I set the settings for either the sop geometry, or vortex force operator, the values will not change throughout the simulation. What is the proper method for animating these attributes for use in dops? Thank you,
  11. Hi, It seems that generally when animating objects in scene/object level, you are only able to animate variables globally. I have a scene with a spinning propeller, and this spinning propeller needs to rotate around its own axis, while being placed in a certain spot in the scene. How is this achieved? All transforms in the scene are global space, so if you need to rotate the object 30 degrees on the X axis, the Y axis will not follow the local transforms and the propeller will spin sideways in circles. Followup question: I briefly had a teacher from Lost Boys school of VFX and he showed me how to properly load animation data into a dopnet. Unfortunately I was just starting out with Houdini as he showed me, so I did not catch the method. I gathered that this should not be done in sop-level ('Use deforming geometry'), and rather with motion / 'RBD keyframe active' operators in the dopnet -- how do I load in my animation data, so the velocities are correct with proper interpolation? Thank you,
  12. I'm making an effect very much like this one from Entagma: https://vimeo.com/194277211 I've adjusted it a little and I noticed that some of the curves that get created collapse onto each other. I think it even happens at the very first frame. You can see that by the white parts of the lines. Those are the last created points. When two white parts meet, it means the curves collapsed and continues as 1 curve. What the setup does is it has a bunch of points as the active searching points. Each of these find target points in front of them and saves those in an array. Then a random point from within the array gets chosen and used to make the polywire. Sometimes, mainly at the very beginning, the searching points are close enough together so that they might find the same target points. This is where I believe the issue lies. What I would like to achieve is that I can check between the arrays on each of the points to see if they have similar target points and if so, remove those from one of the arrays. Or that when points get targeted by one searching point, they instantly get marked so that they can't be found again before the end of the timestep/solve. At this moment, I'm still trying to figure that one out. Any tips for this are much appreciated. Eckhart ObjectMaterialize.v005_00.hip
  13. Hi guys, I made simple lightning effects and I want to make all frame of this effects in a single mesh like screen capture. I try to use solver sop and it looks okay but you know, there will be a few same multiple mesh. also don't want use timeshift sop to freeze each frame and merge them. If you know good method please help me!! Thank you!
  14. I can follow the code written in Tutorial and can be compiled. Parameter can be created. However, there is no way to create an attribute. mycircle.h #include <SOP\SOP_Circle.h> #include <OP/OP_Parameters.h> class SOP_MyCircle : public SOP_Circle { public: SOP_MyCircle(OP_Network *net, const char *, OP_Operator *op); static OP_Node *MyConstructor(OP_Network *net, const char *name, OP_Operator *op); static OP_TemplatePair *buildTemplatePair(); protected: OP_ERROR cookMySop(OP_Context &context); private: fpreal COLORX(fpreal t) { return evalFloat("color", 0, 0); } fpreal COLORY(fpreal t) { return evalFloat("color", 1, 0); } fpreal COLORZ(fpreal t) { return evalFloat("color", 2, 0); } }; mycircle.cpp #include <UT/UT_DSOVersion.h> #include <OP/OP_OperatorTable.h> #include <OP/OP_Operator.h> #include <OP/OP_Context.h> #include <OP/OP_Network.h> #include <SOP/SOP_Node.h> #include "mycircle.h" #include <stdio.h> static PRM_Name colorName("color", "Color"); static PRM_Default colorDefaults[] = { PRM_Default(1), //r PRM_Default(0), //g PRM_Default(2) //b }; static PRM_Template newParmsTemplates[] = { PRM_Template(PRM_RGB, 3, &colorName, colorDefaults), PRM_Template() }; OP_Node *SOP_MyCircle::MyConstructor(OP_Network *net, const char *name, OP_Operator *op) { return new SOP_MyCircle(net, name, op); } SOP_MyCircle::SOP_MyCircle(OP_Network *net, const char *name, OP_Operator *op):SOP_Circle(net, name, op) { } OP_TemplatePair *SOP_MyCircle::buildTemplatePair() { OP_TemplatePair *old, *my; my = new OP_TemplatePair(newParmsTemplates, 0); old = new OP_TemplatePair(SOP_Circle::myTemplateList, my); return old; } OP_ERROR SOP_MyCircle::cookMySop(OP_Context &context) { SOP_Circle::cookMySop(context); fpreal now = context.getTime(); fpreal clr_r = COLORX(now); fpreal clr_g = COLORY(now); fpreal clr_b = COLORZ(now); GA_Attribute *cd_attr = gdp->addFloatTuple(GA_ATTRIB_PRIMITIVE,"Cd",3); GA_RWHandleV3 h(cd_attr); GA_Offset off = 0; h.set(off, UT_Vector3(clr_r, clr_g, clr_b)); return error(); } void newSopOperator(OP_OperatorTable *table) { table->addOperator( new OP_Operator("myCircle", "myCircle", SOP_MyCircle::myConstructor, SOP_MyCircle::buildTemplatePair(), 0, 0) ); } mycircle.cpp
  15. I'm trying to imitate the motion of rocks falling on dirt. Since the RBD Solver seems to give me more accurate and realistic looking results over the Bullet Solver, I decided to go with that method using RBD Fractured Object. When I first had my scene setup with Bullet, I was able to use a little VEX in the SOP Solve to artificially reduce velocities as rocks fell below a certain Y value. It seems like that setup isn't compatible with my RBD setup, so I was wondering what would I need to do to get it working? In addition, how can I write an expression that would tell the solver to reduce the velocities of the objects by half and double their weight each time they impact the ground? Any tips would be greatly appreciated. Thank you! RBDTest_001.hiplc
  16. Condision in SOP ?

    is there any solution for make a condition in sop level ? for example i have a loop (based on connectivity) and inside that i want to add pollycap on only objects which have unshared edge. is this possible to do it in houdini sop ? thanks
  17. I've laid out UV's procedurally in Houdini with the sweep or skin sop and using arclen on the input curves, but I'm wondering if there is a solution to straighten/unwrap geometry that is generated in ways other that using a sweep or skin SOP. If anyone is familiar with the Unfold Strip from Loop button in 3dsMax's Unwrap UV modifier it basically takes any edge or loop input and straightens out the geometry into a strip. It's super useful for cylinders and chamfered/extruded edges. I'm wondering if there is a workflow to do something similar in Houdini. I tried messing with the new FlattenUV node and I can get something kind of close with the enable loop straightening, but the UV's are still wobbly and not perfectly straight.
  18. Hey all, I'm super new to Houdini with a background in game development. I was going through tutorials on pluralsight and I'm loving it so far. So I've been expanding on the content and diving into Vex, and I hit a snag trying to run a Solver that changes generated point colours, because I wanted read from and modify persistent data on a separate point outside of the solver network. I simply created details on the point in an Attribute Wrangle in dataHolders and thought it would be easy to read and write to them from an attribute wrangler infectedPoints in the solver. The problem is the vex script in the attribute wrangler can't actually read the details ie: int pointsVaccinatedSoFar = detail("../../../dataHolders/dataHolderPoint","pointsVaccinated",0); int maxPointsToBeVaxxed = detail("../../../dataHolders/dataHolderPoint","maxPointsToBeInitiallyVaccinated",0); printf("points Vaxxed so far: %g\n",pointsVaccinatedSoFar); printf("points Vaxxed so far: %g\n",maxPointsToBeVaxxed); The font node pulls the details properly and prints them. But the printf always yields 0 when maxPointsToBeVaxxed should be 10. I'm guessing I'm breaking some kind of data context/scope protocol in Vex buuut I don't know enough about Houdini yet to really understand what's going on if that's the case. Or I guess I'm not using detail() properly, or both Any help would be appreciated! I'm using Houdini Indie so if you guys can read it I can upload the .hiplc file. Thanks!
  19. Probably a very noob question... but what are the differences and benefits of the two ? They both run a simulation over a SOP network... are they any different in what they can achieve ? Thanks! J
  20. Im trying to connect an apply data to a sop solver (even the documentation page of the sop solver says that one of the most common inputs is the apply data node) but no matter what I always get a "Connection to input 0 is the wrong type". The only solution I found is to go through a multisolver node... which is fine but I wish I could understand what's wrong with connecting an apply data node directly to a sopsolver ?? What I would like to do but returns error (despite documentation): The solution I found: Thanks! J
  21. Hi everyone! I'm relatively new to Houdini, and I came across a tutorial which explained the bullet solver for H13. I am trying to recreate the effect that he got at 53:15, where primitives were deleted from the constraint network when a force over a certain threshold was applied. tutorial: As I understand, the SOP solver was changed in H14, and I therefore don't have the object merge node that he has. I downloaded the example HIP file and copied his node into my own project and managed to get it working, however I'd like to know how it actually works, rather than just copying and pasting! The data that the node is bringing in, is as follows: `stamps("..", "DATAPATH", chsop("relnode") + ":Relationships/" + chs(chsop("relnode") + "/relname") + "/" + chs(chsop("relnode") + "/relationship/dataname") + "/Geometry")` This isn't like anything I've come across so far in houdini - if anyone knows what this means, and could explain it I'd be very grateful! Best, Stephen
  22. N-body via SOP solver with OpenCL

    Here is it.:) nbody_opencl.hipnc
  23. I'm trying to drive a BlendShapes' SOP blend parameter using a point attribute, @fade. The @fade is a point attribute and have it's value animated. But the blend parameter doesn't appear to read this animated values and keep showing 0 instead. The question: the blend parameter doesn't work with point attributes? I tried VEX and Hscript forms (@fade and $FADE). The second crashes.
  24. I need an advice from you, guys! How the local attributes of PolyExpand2D SOP are to be used? I want to make a non-uniform offset with these inside scale attributes. But I do not know the workflow for this.
  25. Hey all, Sorry to add another Python cooking question (I've seen a lot, searching), but here goes. I have two subnets, a 'source' (from an .fbx) and a 'target'. The Objects in each correlate by name, and those in the source subnet are keyframe-animated. I'm driving the target Objects via: sourceMg = sourceNode.worldTransform() # beep boop, additional calculations go here targetNode.setWorldTransform(sourceMg) It works great, but once Houdini caches the frame the script is no longer (apparently) cooked, which makes sense--I pasted my code into a Python Script Object for convenient testing, which I suppose is not its intended use. If the HOM documentation is telling me what to do instead, however, I don't see it. There's the 'Python object' page, but I don't know that this is quite the same. In short: my script works as intended, but after the scene plays through once, Python stops moving the target nodes (I'm guessing because Houdini quits cooking it, since it's not doing anything Houdini expects it to do, like make geometry). Where does a script like this belong? I'm sure there's something embarrassingly obvious I'm missing--it's just a little extra confusing to me because I have to manipulate everything on the Object level. Thanks in advance for the help! If anything's unclear, lemme know
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