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Search the Community: Showing results for tags 'rotate'.

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Found 14 results

  1. hi, I know how to do some basic rotations with vex although the objects is always rotation around itself. Is it possible to do the same thing but use an external rotation point e.g. one of the corners of the box ?
  2. Hi there, I have been trying to figure this out but probably don't know enough about transform/rotate matrices and how they work. What I got is a circle of flat boxes all orientated in Z. The flat side is always faced to the center of the circle. See attached image for better understanding. Now what I want is a rotation around the local X axis of each box. Attached is an example file to see what should happen and also what I have come up so far. To better illustrate what the end result should be there is the same setup built with a copy SOP and a transform node before to do the rotation. Now the solution I came up with kind of works. The main problem is that there seems to be some sort of scaling. You can see this when viewing the solution made in Houdini in template mode. Maybe someone can point me in the right direction. Also, my setup is not very elegant so if there are other or better solutions I would love to hear them. Thanks in advance! Dennis rotate_objects_local_v01.hiplc
  3. Hi EVERYONE : Maybe this tutorial is not very short, watch it completely, i am sure that you find new stuff about matrix and you will learn new technique .Hope you find it useful !!! Hossam Aldin Alaliwi more training here : www.hossamfx.org
  4. Hi guys! I've made a sim with particles but I would like to keep them rotate in circle for some seconds and then use their inherit velocity. how i can keep them rotating? i've been trying to add angular velocity with cos ($T * 180) ty = sin ($T * 180) this expression, but doesnt seem to work. any suggestions? thanks!
  5. This has been a very hard search to find an answer to. What I'm trying to do is add an initial spin/rotation to a DOP object. I attached a simple scene of a torus that has an initial upward velocity and then just falls to the ground due to gravity. Essentially, I'm trying to give it a "punch" that will cause it to spin - but not perpetually. A good example would be if you had an object that hit "glass." Although the sim would be physically correct, to add interest it would be nice to add a little spin force to the shards of glass on the initial impact. I can't for the life of me find a way to do this in DOPs. I'm sure I could be overlooking the most obvious parameter, but it's also Houdini and sometime the simplest task takes some finagling. Any help is appreciated! DOP_spin.hipnc
  6. I'm trying to mess around with orienting a particle's alignment to it's vector. Or a watered down version would be a cube on a path that follows it based on the particle's vector or velocity. Basically, orienting the particle to "speed space" if that makes sense? I tried mixing Normals and Velocity to possibly get them aligned but I'm pretty much lost. I took a look at @mestelahere to help me out, but I'm pretty much in over my head trying to do it in Houdini. I attached my file that is just a spinning circle with box's copied onto them. I was trying to make a simple scene where the boxes rotation matches it's vector. So nothing too out of the ordinary, but still kind of confusing. Thanks :)! velAlign.hipnc
  7. pre random rotation then orient.. hi!Some questions,just can`t get this effect in instance!could anyone help~!thx! rotate_in_copy_H15.hip
  8. Hi. Guys. I met a problem, There was a bent tube i want rotate it along itself. I make a sketch to help understand. D: The problem was i need do it by maketransform node of pointvop, i initial the pivot, but i can't set the rotate right. So if anyone can give me a hint will be great. Thanks. maketransform.hip
  9. Hi Folks! This is my first post here! I'm returning to Houdini after a break only to find that POPs have changed a lot... I'm stuck on one little thing - POPspin. I have a very simple AutoDOP network - (location - POPsprite - POPsolver) in POPsprite I have a VEXpression (spriterot = rand(f@id)*360) which sets the sprite angle to random. I want to give each sprite a slight random spin which I have tried to do with POPspin but I have had no joy! Should POPspin come before or after POPsprite? (at the moment neither works...) Any help welcomed, Thanks S.
  10. I want to copy objects on points and randomize them in rotation (e.g. Y axis) from 0° to 360° but in 90° steps. I think I need kind of an expression like " (round(rand($PT))*90)" but this gives me only 0° or 90°. I do not quite come up with the right solution for 360°. Would be nice to get some help with that. kind regards Jon rotateIn90degreeSteps.hipnc
  11. hi there, please help me with these, i have spend alot of week for these, and still stucked.. basicly i want to try to rotate perprimitive base, effected by color and rotate some degree..but yeah, im still alot of learning with these.. i have recreated on my daily tools cinema4d, and its just required some step to achive fx that i want...but for some reasond i want more freedom with those fx....so i jump to houdini... please anybody on these forum help me with these... i got help from official site houdini forum...and got helped..but still got error for the rotation... i upload all the file, from the refference video, and all the houdini file i created and got helped... thanks.. help please... the reff video: jk_rotate_with_n_124 (1)_helped.hipnc rotate_per_prim_needHelp.hipnc
  12. Hello everyone, I am trying to recreate the per primitive rotation example i found here with VEX for learning purposes. The example file uses VOP to calculate a quaternion to rotate the points but when i do it in vex something weird happens and points doesn't behave as expected. I have also used qrotate() but no luck. Can you please take a look at file? Am i calculating the quaternion wrong? Thanks in advance Per_prim_rot_vex.hipnc
  13. Hi everyone. I'm hoping one of you clever people will be able to help me with this little problem I'm having. When copy-stamping objects onto some animated points, the copied objects are transformed along with the points, but they do not fully respect the rotations. I have a feeling the solution will require a vopsop, with some kind of vector math to get Y normal rotations, but my knowledge of vector math is very limited and I'm struggling to find an elegant solution. I've created a simple scene to demonstrate the issue. You'll see that the teapots do not rotate along with the grid that they are copied onto. Any help would be much appreciated! rotNotWorking.hip
  14. Hello! I am currently trying to wrap my head around being able to transform (rotate) instance objects for sop copy and instance rendering. Basic stuff, I know, but I'm stuck and my math suck. I have a hard time grasping dot product, cross product, matrices and quaternions -> 3D transforms There are, as far as I can see, a multitude of attributes and options to do this, and I am wondering what would be best suited for my use? Some use up, some use orient. Basically, I would like to have the rotation options of the transform sop (x, y, z rotate) to work on a point instance where the normal direction is the "up" direction (think teapots standing on a displaced ground plane, rotating planar to the ground when editing the y axis). I've been through a lot of examples but I just can't make them work for my scene. Either the objects are flipped or rotation is happening on the wrong axis or objects are not rotating smoothly, or I am not able to figure out how to "flip" to the right axis when using N and up (usually +-90 degrees in x) inside the vop. Most of all, it needs to be stable on deforming geometry. Any example of rotation working in this scenario would be most welcome! Also, if you have a link to a good (basic level) resource regarding this topic, that would be awesome! Thanks.