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Everything posted by Atom

  1. string from relative path expression

    Have you looked at the docs? Try placing the evalAsString inside a TRY/EXCEPT or unexpand the string as the docs suggest.
  2. Houdini Matrix to Renderman Transform?

    So far my code looks like this. Each Houdini node presents 4 matrix options. I am not sure which one to use or what to swap for what? def export_transform(rib_writer, ob_name): n = hou.node(ob_name) if n != None: #mtx = n.parmTransform().inverted() #mtx = n.localTransform().inverted() #mtx = n.preTransform() #.inverted() mtx = n.worldTransform().inverted() rib_writer.emit_text('Rotate 180 0 1 0') rib_writer.emit_text('Scale -1 1 1') rib_writer.emit_text('ConcatTransform %s' % rib(mtx)) Which is kind of close. But compare the two images, one is the Houdini viewport and the pink image is the renderman result. It also looks like the sphere should be 1-y but I'm not sure how to do that with Matrix math?
  3. Hi All, I have been trying to determine what type of material I have in any given node. For instance the difference between a Clay material and a Mantra Surface. Each node does have a .shaderType() method but they both return the same value, vopnetwork... Is there any other method for distinguishing the difference between material nodes other than grunt checking for the presence or absence of parameters using TRY/EXCEPT? Thanks
  4. Determine Material Type From Python?

    Thank you, I think that can work.
  5. Hi All, I have a short python script that is running as a button the SHELF. I have some hard coded strings in my script and it would be nice to move them up one level so an end user could type in values. Can this be done with a SHELF tool or do I have to convert my tool to an HDA?
  6. Can Shelf Tool Have Parameters Panel?

    Thanks for the tips. @mantragora: The ALT-Click might be a way to go for the popup dialog. @michael: I am detecting as much as possible but this is an exporter that calls a 3rd party tool that could be installed on any drive. So some user interaction is probably required to specify where the tool is installed.
  7. Hi All, I ran across this page where Ryan Hurd uses a custom VEX shader to accomplish cross hatch shading. http://hurdfx.blogspot.fr/2005/05/vex-toon-cross-hatch.html I am trying to replicate this effect but I can't seem to figure it out. The above website describes the technique but leaves out a step-by-step which noobies like me still need. Can someone take a look at my HIP file and tell me what I have done wrong or still need to do to create this render effect? I am not sure if it is a shading issue, lighting or both? I have re-constructed the shader as best possible, it is located in the SHOP network. ap_vex_cartoon_hatch_marks.hipnc
  8. Can Shelf Tool Have Parameters Panel?

    Thanks for the link. I guess if I have to use a popup form that would be last choice. The strings in my code are more like properties that get set once depending upon the scene and OS. Then you click the button over and over to use those settings. It would be nice if the SHELF tool had a parameter sheet like nodes.
  9. Hi All, I am trying to make non-sticky UVs. Lay down a grid followed by a UV Texture then a UV Edit. With the UV Edit active select a face and move it along the X axis in the UV viewport. The four points of the face do indeed move but they drag along the faces of the neighbors vertices as well. I don't want this effect. I want each face in the UV map to be an independent 4 point entity that is not connected to a neighbor. I want to be able to move a UV box anywhere on the image and not be related to any other faces. I am still learning Houdini UVs. I wonder if I want each face to be an island...? Not sure of the terminology here. Is there a node that can already do this or does it have to be done in a FOREACH for example?
  10. Python Based Mantra to RSL?

    Hi All, I am wondering if any one has any python code that will convert a mantra surface to a RSL shader? Even a partial implementation could help? Thanks
  11. Python Based Mantra to RSL?

    Thanks for the link. After thinking about it I don't think I need to go all the way to RSL. Maybe something as simple as routine a few of the most common parameters from a Mantra Surface to an already existing ShinyPlastic or Uber shader might just do the trick.
  12. Emulating Toon Cross Hatching?

    Thanks for the feedback. I think I was expecting to see it in the viewport. Now that I have switched to the Render view I can see that it is working.
  13. Dan, care to clarify? I notice that depending upon what projection type I use the UV coordinates appear in different columns in the Geometry Sheet (i.e. Primitives or Points). Is this what you are talking about? Should I use an Attribute Promote to always shift them to Points with the Delete Originals turned on?
  14. What is the User name you are logged in as? Are there non-standard characters in your User name? Sometimes that can cause pathing issues in scripts. If so try creating another user on your system with a simple name like 'test'. After that log in as 'test' user and try the Houdini tool under that user name.
  15. Hi All, I am looking for a way to use a python node to fetch the UV coordinates for a given Primitive. I can get the uv attribute but I m not sure how to gain access to the coordinates. Does anyone have any tips or examples? Thanks
  16. Hi All, I am trying to obtain a list of Primitives that are in the current selection. Mainly right after creating a loop selection. Not sure where to begin on this one...
  17. Thank you, I think that will do it. Your above example scales all UV coordinates in half. So I am still a bit unclear about the return values from Houdini functions. The return value, coord is a tuple, I think. Is that why you need to convert explicitly to a Vector3 on the next line? When fetching attribValues is it expected to test for type of return value before assuming the variable contents?
  18. Is there a way to turn off those annoying RED hud items that have just appeared in the R14 release? For instance, when I am UV Transforming a Soft Radius slider appears in my UV viewport that is linked directly to my middle mouse wheel. Because I am often zooming in and out I use the wheel for that. But sometimes Houdini does not catch the fact I pressed the space bar before sampling the mouse wheel and then my mouse wheel command goes to the slider instead of the viewport. This causes all my selected UVs to joins together in a mess. I know I can set the radius back to zero to recover from this and continue but it is quite annoying and interrupts my workflow. I would like to have no overlays in my viewport, don't get my started on that connectivity box that has no X to close.
  19. Thanks Marty I'll try that. What I wanted all along was the UV Transform instead of the UV Edit. I am happy with the shape of the UVs, just not their location. The UV Transform seems to be what I am looking for. I think Unique Points on the geometry might cause the faces to disconnect when I displace (which I realize I did not mention was a requirement earlier). I still want the faces to stretch.
  20. Hi All, I just watched Manuel's tutorial on the FOR/EACH sop. This tutorial copies boxes. In the end you end up with two possible outcomes. One result is boxes with materials cycling through 3 possible materials. The other result is each box with a random color applied. What I would like to do is mix these two resulting streams using some form of modulus to determine how many of each stream get mixed in to a final single stream of geometry. Example: The first 4 copies come from the 1st stream, the second 4 copies come from the 2nd stream then back to the first stream and so on... How can I do this? I realize I need some groups and way to select alternately from each group. Are there specific nodes I should be using? In the screen shot I have the current result of each stream, one in each object but I would like a single object for the final result. ap_for_each_example.hipnc
  21. Merging Two Geometry Streams Via Modulus?

    That's pretty neat, thanks Petr! I like the way you have broken it out into boxes to show the steps. I had not thought about the deleting part.
  22. Emulating Toon Cross Hatching?

    Thanks for the breakdown on my scene. I made the suggested changes but I still don't get any wireframe effect like posted in the Ryan's image. I'm not sure what to adjust or change next? ap_vex_cartoon_hatch_marks.hipnc
  23. Windows: Render hangs

    I have experienced similar issues when rendering on OSX. The culprit for me was power saving. Turn all that crap off. Turn off screen saver and make sure the computer never, ever, ever goes to sleep. OSX recently introduced AppNap, yet another way for the system to determine if a program is really running. You can turn that off on a per-app basis.
  24. PYRO on GPU OpenCL crash

    Dang, OSX left out of the loop again...?
  25. Could you just add an Extra Image plane to your render? Choose direct lighting, then under Light Exports select Export variable for each light. There is even a light mask field that appears if you need to isolate each light. Make an Extra Image plane for each light with a unique light name in each mask field..