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Technical Discussion » Blend Shapes SOP to blend from static to anmated mesh
- mrCatfish
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Can you explain a bit more what you are trying to do? Simply blending between the T pose and the animated pose will result in the geo moving linearly to the target position… not at all natural and all sorts of intersections will result.
Technical Discussion » How to assign material to scattered objects?
- mrCatfish
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Technical Discussion » copy to points objects can't be bounding box?
- mrCatfish
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You can only group points to use as bounding objects… are you trying to create a point group?
Technical Discussion » opdef woes
- mrCatfish
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In the long tradition of answering my own question… the problem was in the script I wrote. I failed to properly construct the conditional statements. If the numbers are not in quotes, the script will break, (I guess the integers are being passed to the script as strings, and the tests sometimes don't evaluate). I don't know why sometimes they do evaluate, but coming out of the fog of my memory, I remember this as a long-standing hscript issue.
unix echo "----" unix echo $argc unix echo $arg1 unix echo $arg2 if ($arg2 == "0") then unix echo zero endif if ($arg2 == "1" ) then unix echo one endif if ($arg2 == "2") then unix echo two endif
Edited by mrCatfish - Dec. 14, 2018 10:51:12
Technical Discussion » Enabling/Disabling bind export in point VOP
- mrCatfish
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Yup that worked.
I'm putting the workflow here for posterity's sake.
I'm putting the workflow here for posterity's sake.
- In the hscript callback of the button:
opdef:.?flip `ch("exportN")`
- In the node tab I added the node I will be modifying the the “editable nodes” parm
- In the “extra files” tab I added a new hscript section called “flip”
- The code for that is:
if ($arg1 == "1") then opparm ./rotate_normals vex_outputmask ("*") else opparm ./rotate_normals vex_outputmask ("* ^up") endif
Edited by mrCatfish - Dec. 14, 2018 10:41:00
Technical Discussion » opdef woes
- mrCatfish
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Hi,
I'm trying to refer to an embedded script in an HDA using an hscript callback.
I want to pass on the full path to this node and the value of the widget that is calling the script:
… this kind of works. If I go from entry 0->1, it works, but if I go from entry 1->2 it does not (script does not even get called according to my debug statements). If I go from 0->2 it gives me the right path to object but the wrong parm value.
I think there is some kind of fancy syntax built into the opdef expression that passes on both the full path and the parm value, but for the life of me I can't find it.
help?
Sean
I'm trying to refer to an embedded script in an HDA using an hscript callback.
opdef:.?foo.cmd
I want to pass on the full path to this node and the value of the widget that is calling the script:
opdef:.?foo.cmd `opfullpath(".")` `ch("parm")`
… this kind of works. If I go from entry 0->1, it works, but if I go from entry 1->2 it does not (script does not even get called according to my debug statements). If I go from 0->2 it gives me the right path to object but the wrong parm value.
I think there is some kind of fancy syntax built into the opdef expression that passes on both the full path and the parm value, but for the life of me I can't find it.
help?
Sean
Edited by mrCatfish - Dec. 13, 2018 17:30:14
Technical Discussion » Enabling/Disabling bind export in point VOP
- mrCatfish
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I have a VOP network that has a bind export. Sometimes I want to export the attribute, and sometimes I don't, (using a toggle). I can't see any way to do this… I tried an elaborate if statement in the callback with opwire and unwires, but it doesn't work, (although it works in the textport).
I'm petty sure this is possible, I just don't remember how.
I'm petty sure this is possible, I just don't remember how.
Technical Discussion » Mental ray not working in maya 2016
- mrCatfish
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This is the reason big studios have elaborate pipelines so that each package and its dependencies run it their own subshell and are conflict free. Of course, this does not help you, but it's long been an issue. One thing that drove us nuts in the early days of CG pipelines was the LD_LIBRARY_PATH for each package being different and stomping all over each other.
In the short term, just renaming the houdini install folder or the maya install folder when you are using one or the other will take it out of the path (as the path to the files will no longer exist) and hopefully work. This would mean that you can't run them both at the same time though.
In the short term, just renaming the houdini install folder or the maya install folder when you are using one or the other will take it out of the path (as the path to the files will no longer exist) and hopefully work. This would mean that you can't run them both at the same time though.
Technical Discussion » I copied box to line points. Different line direction got a wrong result.
- mrCatfish
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I assume it's the twisting you don't like? I think it looks cool, but if that's not the desired result, you need an up vector in addition to your N.
Add a “attribute create” after the pointVOP1, call it “up,” and make it a vector. Set it to 0,1,0. The planks will untwist.
Reason is that N aligns the copies, but the orientation is ambiguous. Without it, Houdini just guesses and they will spin and do other weird things. Creating an up vector gives it a frame of reference.
Add a “attribute create” after the pointVOP1, call it “up,” and make it a vector. Set it to 0,1,0. The planks will untwist.
Reason is that N aligns the copies, but the orientation is ambiguous. Without it, Houdini just guesses and they will spin and do other weird things. Creating an up vector gives it a frame of reference.
Edited by mrCatfish - Dec. 3, 2018 17:09:11
Technical Discussion » Is there a way to get the lowest Y position among a group of points?
- mrCatfish
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Easiest way way is to append an attribute promote to your node. Set it to:
Now you can access this detail attribute somewhere else using:
- Original name: P
- New class: detail
- Promotion method: minimum
Now you can access this detail attribute somewhere else using:
detail("../nameOfSop","P",1)
Edited by mrCatfish - Dec. 3, 2018 16:58:45
Technical Discussion » Mantra Displacement Issue
- mrCatfish
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We've had lots of trouble with displacement unless we turn on “full predicting” at the object level, (dicing tab).
Technical Discussion » CopyToPoints vs Instance OBJ node with High Point counts
- mrCatfish
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Here is a great treatise on this topic: http://www.toadstorm.com/blog/?p=493 [www.toadstorm.com]
Technical Discussion » Is there a conflict of interest at SideFx over scene scale?
- mrCatfish
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I agree that this is confusing. For examples, complex bullet sims of things about 1m in size result in collisions jittering all over the place and never settling. So you have to scale up 10x and scale all your forces and it's fine. At this point I am considering just telling my students to do everythng at 10x scale.
Technical Discussion » Updating environment variables
- mrCatfish
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Use “varchange”. This will update the nodes. I don't see a Python equivalent, so you'll have to use hscript.
http://www.sidefx.com/docs/houdini/commands/varchange.html [www.sidefx.com]
http://www.sidefx.com/docs/houdini/commands/varchange.html [www.sidefx.com]
Technical Discussion » How to propagate a hou.NodeError to the enclosing hda
- mrCatfish
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Once an HDA, go to the “Node” tab, and select the python SOP as a “Message Node”. All errors will be propogated to the top level.
Technical Discussion » Volume Light
- mrCatfish
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Having some trouble with the volume light. Basically, sometimes it works, sometimes it does not work. This thing seems to be strangely black-boxed.
New Houdini, sphere, then shelf tool “explosion.” Then shelf tool “volume light”. Do a render, see some grainy lighting. Play with all parms, zero change to the look.
So I thought I'd just make sure to cache the pc sequence to disc. So I put “/tmp/cache.$F.pc” in the point cloud file parm. Render, then I look in /tmp, there is nothing there. Even closing the hip file and opening it and re-rendering, still nada.
Okay, so I turn “enable point cloud” off and on… zero visible change in renders, (not doing interactive renders).
I turn the intensity and exposure way up and way down… again, zero change.
I am also seeing lots of this in the shell:
So I scatter some points into the volume, (density field), save them to disc with .pc suffix, and then use those in the volume light. Repeat all of the above, no change.
The only time I can affect the look of the scene with this light is by toggling it on and off, (where I see no lights at all of course, and a really bad, grainy volume render). All other changes result in no changes to any render.
Anyone have any tips or trick on working with this thing?
Sean
New Houdini, sphere, then shelf tool “explosion.” Then shelf tool “volume light”. Do a render, see some grainy lighting. Play with all parms, zero change to the look.
So I thought I'd just make sure to cache the pc sequence to disc. So I put “/tmp/cache.$F.pc” in the point cloud file parm. Render, then I look in /tmp, there is nothing there. Even closing the hip file and opening it and re-rendering, still nada.
Okay, so I turn “enable point cloud” off and on… zero visible change in renders, (not doing interactive renders).
I turn the intensity and exposure way up and way down… again, zero change.
I am also seeing lots of this in the shell:
[15:26:22] mantra: Point cloud handle referenced before it was opened. Was pcopen() called? [15:26:48] mantra: Point cloud handle referenced before it was opened. Was pcopen() called? [15:26:57] mantra: Point cloud handle referenced before it was opened. Was pcopen() called?
So I scatter some points into the volume, (density field), save them to disc with .pc suffix, and then use those in the volume light. Repeat all of the above, no change.
The only time I can affect the look of the scene with this light is by toggling it on and off, (where I see no lights at all of course, and a really bad, grainy volume render). All other changes result in no changes to any render.
Anyone have any tips or trick on working with this thing?
Sean
Edited by mrCatfish - Sept. 13, 2018 15:54:54
Technical Discussion » Paint Active Attribute
- mrCatfish
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If you put “Cd” in the transfer attributes field when assembling (with “pack” option on), and follow the advice above, you should be golden.
Technical Discussion » [Solved] [ROP] Can a pre-render script prevent the ROP to render?
- mrCatfish
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Technical Discussion » How to mirror animation from FBX animated character in CHOPS
- mrCatfish
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Can you post a hip file? In short, it sounds like you just want to rename your channels so the left hand fist pump becomes a right-hand fist pump?
Technical Discussion » Principaled Shader: Displacement -> Custom Input
- mrCatfish
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