Jump to content


  • Content count

  • Donations

    0.00 CAD 
  • Joined

  • Last visited

  • Days Won


Everything posted by j00ey

  1. 16.5 drums

    Oh great, I kept meaning to put persistent quickmarks on the H17 wishlist... someone must have done it for me
  2. 16.5 drums

    It appears to be out...
  3. Some DOPs RnD

    Thanks! I love the stuff you've been posting on here too - fantastic work!
  4. I figured this out, i guess I must have figured it out last time and just forgotten... I made a scene file in case it's useful to anyone. The pc file needs to go in a 'cache' subdirectory of wherever you download the scene to, ie $HIP/cache/butterfly_pts.pc butterfly_pts.pc displacement_pcLookup.hip
  5. Has something changed with the new H16 mat way of doing displacement that would cause problems with point cloud lookups? I have a shader [a modified classic shader] in which I'm looking up a point cloud to get some wetness and colour attributes and it works fine without displacement. As soon as I switch that part on though, all the wetness etc vanishes. I'm sure when I've done this before it just worked but I'm clearly missing something. I'm transforming global P from current to object space to do the pc lookup, I don't recall having to do any compensation there for the fact that the geo is displaced. Does anyone have any pointers..?
  6. Hi I'm having a problem with a cone twist constraint network. I'm setting all the axes per constraint in SOPs (goal_twist_axis, constrained_twist_axis etc) and I wanted to set the motor_target values inside a SOP solver in my DOP network but it's just not doing anything. I can set motor_enabled and that works fine. I've tried v@motor_target, v@motor_targetr, f@motor_targetry, nothing gets picked up. I can't find anything in the docs or online... Any ideas?
  7. Ah yes thanks! I was looking at the Geometry but of course until you set a value manually, there's nothing there. Much appreciated.
  8. I see - I just tried setting it with a quaternion and it's doing something! Thanks very much for the pointer. Where do you see that in the spreadsheet though to be able to tell you have to set it with a quaternion instead of a vector?
  9. Ah thanks - that's interesting, I'll try that. But on initial inspection, my goal_twist_angle etc attribs aren't converted to quaternion. Where are you seeing that happening?
  10. Well I'm actually not trying to achieve anything in particular, I'm learning some RBD stuff, specifically constraints and was looking into the cone twist. I think it may be a new thing but it does now have a motor capability and it does work globally [to be honest I'm still trying to understand what it's really doing] but per-constraint doesn't. I just copied the name from the related param field in the same way you can find the names like goal_twist_axis etc and indeed i@motor_enabled works but I couldn't work out the motor_target.
  11. Export animation data to JSON

    @f1480187's method is indeed much cleaner. Here's an updated file in case it's useful. basic_json01.hip
  12. Export animation data to JSON

    Thanks very much for the tip, I will look at that.
  13. Export animation data to JSON

    I made you a basic file to start you off - I'm not very advanced in python myself so don't take this as the proper way to do something, it's just a way... If you open a python shell and click on the 'Print JSON' button, you should get some JSON printed out. Look in the python module of the asset to see how it's set up. basic_json.hip
  14. Export animation data to JSON

    It depends on what the software you're reading it back in with wants. I was writing it out for a custom renderer so the developer gave me a template to use as a guide and I matched that, filling in the data from geometry attributes and transforms etc. I guess if you just want translation, rotation etc you can use worldTransformAtTime() to get the transformation matrix at a given frame, then use extractTranslates(), extractRotates() to get the values for each frame [or time step] that you want to sample. Check how the reader expects your JSON to be formatted and match that - eg [if my memory serves] I had to write the point positions as one long array of comma separated values that the reader parses in groups of 3 [x, y, and z], so that meant looping through the points, getting the positions, stripping off the brackets, appending to the array then putting square brackets around the array. The site I posted last time was very useful for checking I hadn't missed a comma or bracket somewhere. If you have experience with python I think it should be fairly straightforward, if not [like me] use the docs...
  15. Export animation data to JSON

    I've just been working on an exporter to write out geometry descriptions and animation data for a realtime renderer and found it was quite manageable using python, the thing that can get tricky to get right is the formatting - square brackets, curly brackets, commas etc. This site might come in very handy for checking your output : jsonlint.com
  16. wedge rop doesn't wedge properly

    Sorry, I hadn't noticed before but I think you just need to turn on 'Initialise Simulation Ops' on the Geometry ROP. I just tested it and it came out as expected.
  17. wedge rop doesn't wedge properly

    I can't see anything set wrongly in your wedge ROP. Did you try turning off caching on your DOP network then running the wedge?
  18. I'm having a little difficulty with some matrix maths. I have 3 points P0, P1 and P2 [as in the attached drawing] and I need to find the point on the line between p0 and p1, such that the line from it to P2 is perpendicular to it. The way I tried is to first find the angle between P0-->P1 and P0-->P2 [acos of the dot product], then from there find the lengths a, o and a using trig, from there it's simple to find the correct position but somewhere or other I'm going wrong. I'll persevere but I wondered if there is some standard function to find that position, I imagine it must be a common thing to want to do... Thanks in advance
  19. Calculate perpendicular vector

    I don't have that particular file to hand any more but I made you a file to demonstrate an easier method. If you take the dot product of the normalized vector P0->P1 in the drawing above, and the UNnormalized vector P0->P2 that will give you the magnitude of the vector in the (normalized) direction P0->P1 that the perpendicular projection point is. That's probably a bit garbled but if you look at the file I hope it will make sense... projection.hip
  20. I'm making an HDA and I need to have a couple of different modes, each of which need a translation control. I don't really want to have more than one visible at any one time to avoid confusion and all my UI hides and unhides itself according to what mode the user selects but I can't figure out how I can hide handles. The documentation is a bit sparse - i suspect it might be something to do with the ''onoff'' field but the ''disable when'' syntax doesn't seem to work... Does anyone know more how they work? Thanks for reading
  21. Disable when doesn't work for handles it seems - unless my . I'm not talking about parameters, I want to hide a handle.
  22. Calculate perpendicular vector

    I figured it out, I had a plus instead of a minus...
  23. Hi I've been banging my head on a wall trying to wedge a load of sections of a cloudscape and figured out that something inside the sky SOP seems to be causing the problem. If I make a standard VDB from poly andf write it to disc, it's fine but whenever I try and write a density VDB created by the sky SOP it comes out at 1Kb. IS it something to do with the CVEX shader inside it? I've tried using my standard VDB and using volumesample to get the density value from the sky but that also writes as a 1Kb file. Attached is a mockup file to make things clearer. Thanks in advance for any ideas... skybox_clouds_ODFORCE.hip
  24. In case anyone else comes up against this problem, I found a workaround - go inside the sky SOP asset and copy and paste the contents of the CVEX shader builder inside shopnet/sky into a new volume VOP, then copy the parameters across. A bit of a hack but it's writing out properly now at least..
  25. I'm having difficulty with flipping normals when copying geometry onto points. I have a scene with a number of randomly generated structures, just points [each has the same number of points] and I have a CHOP setup to interpolate between them - basically a glorified blendshape - and after the interpolation I'm copying geometry on to them. The problem is that if I use the normal to orient the copies, it sometimes flips, as in the attached scene. I thought if I brought that into CHOPs and added a quaternion attrib with the attribute CHOP it might fix that problem but it doesn't seem to make any difference. Does anyone know a good way to approach this? odforce_flipping_geo.hip