hmmm...
My method would be to apply the original image onto a grid. Each primitive representing the pixel with the opacity value. From there, you could use some vex to get what resolution you need to fit the opaque section and forward those info into a COPs network.
Sorry for being super vague but I don't have the time to go into details...
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Technical Discussion » Trim transparent pixel out of an image in COP
- olivierth
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Technical Discussion » Chain node alignment
- olivierth
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Hi!
Go into your Chain node under the Alignment tab. Make sure the Center Geometry on Curve is unchecked.
Then, you just need to move the original box on the Y or Z axis.
Go into your Chain node under the Alignment tab. Make sure the Center Geometry on Curve is unchecked.
Then, you just need to move the original box on the Y or Z axis.
Technical Discussion » Vex: Fix Backslashes into Frontslashes
- olivierth
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Hi!
I've posted about this about 2 years ago and found the solution. Sadly, I'm getting into the same problem and the solution doesnt work this time.
I've got a path with backslashes that I want to convert with frontslashes. It's not working and I don't get why...
Here's the old post about it: https://www.sidefx.com/forum/topic/85105/ [www.sidefx.com]
I've posted about this about 2 years ago and found the solution. Sadly, I'm getting into the same problem and the solution doesnt work this time.
I've got a path with backslashes that I want to convert with frontslashes. It's not working and I don't get why...
Here's the old post about it: https://www.sidefx.com/forum/topic/85105/ [www.sidefx.com]
Technical Discussion » Arnold's UV Transform: How to use it?!
- olivierth
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Arg! Thanks.
I searched this forum and did not go to the second page. Ok, now I remember how funky this node is... You have to connect image -> UV_Transform instead of UV_Transform -> image!
Here's the page for anyone else:
https://www.sidefx.com/forum/topic/88787/ [www.sidefx.com]
I searched this forum and did not go to the second page. Ok, now I remember how funky this node is... You have to connect image -> UV_Transform instead of UV_Transform -> image!
Here's the page for anyone else:
https://www.sidefx.com/forum/topic/88787/ [www.sidefx.com]
Technical Discussion » Arnold's UV Transform: How to use it?!
- olivierth
- 1007 posts
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Hi!
I've tried using this node multiple time over the year and never got to make it work. I need it to rotate the texture on my geo.
When I connect it to the uvcoods of my image node, it doesnt work. I see one single color for the whole geo. If anybody has used this before, please help me!
-Olivier
I've tried using this node multiple time over the year and never got to make it work. I need it to rotate the texture on my geo.
When I connect it to the uvcoods of my image node, it doesnt work. I see one single color for the whole geo. If anybody has used this before, please help me!
-Olivier
Technical Discussion » VDB from Polygons: non-watertight geos?
- olivierth
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Technical Discussion » Geo Parented to Camera: Only Updates When I Stop Moving Cam
- olivierth
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ARg... I was parenting spheres to the camera (for a turntable). When I check the Export View Continuously, the spheres follow as I move the camera but there's a huge lag with the geometry. Its not smooth like you. Oh well...
Thanks for the info!
-Olivier
Thanks for the info!
-Olivier
Technical Discussion » Geo Parented to Camera: Only Updates When I Stop Moving Cam
- olivierth
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Hi!
I'm used to parenting geos to the camera in Maya where I cant move the cam freely and the geo follows perfectly. In Houdini, it only updates the geo position when I stop moving. Is there a way around it?
-Olivier
I'm used to parenting geos to the camera in Maya where I cant move the cam freely and the geo follows perfectly. In Houdini, it only updates the geo position when I stop moving. Is there a way around it?
-Olivier
Edited by olivierth - March 13, 2024 10:09:04
Technical Discussion » VDB from Polygons: non-watertight geos?
- olivierth
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Hi!
I'm converting an asset to VDB but some geos have no thickness (non-watertight). I remember seing some node/option to deal with those geos. It would give it thickness in a smart way... Know anything about this?
-Olivier
I'm converting an asset to VDB but some geos have no thickness (non-watertight). I remember seing some node/option to deal with those geos. It would give it thickness in a smart way... Know anything about this?
-Olivier
Technical Discussion » HDA Parameters: Disable if there's a Geo in Second Input?
- olivierth
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Technical Discussion » HDA Parameters: Disable if there's a Geo in Second Input?
- olivierth
- 1007 posts
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Hi!
I often use the Disable When section but this time, I want it to disable if theres geo in the second input. What should I write?
-Olivier
I often use the Disable When section but this time, I want it to disable if theres geo in the second input. What should I write?
-Olivier
Technical Discussion » Vex: calculate g force vector?
- olivierth
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Hi!
I'm making a simple car rig and I'd like the body to tilt depending on the G force (Acceleration, turning, etc.). Is there already a node for that? If not, how would I calculate it? I'm guessing I start with a Trail sop to get v@v but what would be the next steps?
-Olivier
I'm making a simple car rig and I'd like the body to tilt depending on the G force (Acceleration, turning, etc.). Is there already a node for that? If not, how would I calculate it? I'm guessing I start with a Trail sop to get v@v but what would be the next steps?
-Olivier
Technical Discussion » Point following path: very chaotic speeds?{[SOLVED]}
- olivierth
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Ah, found it. My "Pin to Animation" settings in the Vellum hair sop was wrong. I needed to have:
Pin Type : Permanent
Orientation Pin Type : Soft
Pin Type : Permanent
Orientation Pin Type : Soft
Technical Discussion » Point following path: very chaotic speeds?{[SOLVED]}
- olivierth
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Oh! From the top view, I can see the root doesnt follow the path perfectly after the vellum solver. When I check before the vellum solver, it's perfectly following the path.... ?!
Technical Discussion » Point following path: very chaotic speeds?{[SOLVED]}
- olivierth
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I used you logic but kept the carve sop. That way, I can still use a graph editor to modify the animation speed. I end up with a very smooth animation. The velocity looks good (doesnt change too much from frame to frame).
BUT! I noticed another problem. My line (the antenna) has a smooth animation. The X and Z positions are animated but Y stays at zero for the whole anim but after the vellum solver, I can see the root point jumping up and down on Y axis. It's like the vellum solver sop is not precise.
Any idea how to solve that?
BUT! I noticed another problem. My line (the antenna) has a smooth animation. The X and Z positions are animated but Y stays at zero for the whole anim but after the vellum solver, I can see the root point jumping up and down on Y axis. It's like the vellum solver sop is not precise.
Any idea how to solve that?
Technical Discussion » Copy-To-Point : Normals are not affected [{SOLVED}]
- olivierth
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I've never heard of "tuples" before. But I can see a difference between my point normal and a normal sop. When I middle click my custom normals, I see N3flt. When I middle click the normal sop, I see N3flt(Nml). I'm guessing that's the "tuples" you talked about.
I noticed that if I put a normal sop on my points, it doesnt affect my normals (there's not polygons so it can't recalculate a vector) BUT, it adds the "Nml" when I middle click. Now, all works perfectly!!
I noticed that if I put a normal sop on my points, it doesnt affect my normals (there's not polygons so it can't recalculate a vector) BUT, it adds the "Nml" when I middle click. Now, all works perfectly!!
Edited by olivierth - Feb. 29, 2024 15:47:37
Technical Discussion » Point following path: very chaotic speeds?{[SOLVED]}
- olivierth
- 1007 posts
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The velocity is something I generated from the animation so I could figure out what's happening. The velocity doesn't affect anything so blurring that would change nothing.
Technical Discussion » Point following path: very chaotic speeds?{[SOLVED]}
- olivierth
- 1007 posts
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Hi, I wanted to animate a point moving on a zig-zag path at constant speed and later attach a line (with 2 points) to that animated point to simulate an antenna of a car.
The main problem is the animation of the point following the path. I can see the velocity is a bit chaotic. It's not much but when I simulate the antenna, it's super obvious. To give an exemple here are velocities 3 frames in a row:
f66 v13.8136
f67 v14.0461
f68 v13.5684
To make the point animation, I did these steps:
1. create a zig-zag curve
2. resample with Treat Polygons As Subdiv Curves
3. Carve sop with First U animated from 0 to 1 (constant anim curve)
4. Create point that always gets its position from point Zero of the carve curve
What should I do to get a smooth anim?
The main problem is the animation of the point following the path. I can see the velocity is a bit chaotic. It's not much but when I simulate the antenna, it's super obvious. To give an exemple here are velocities 3 frames in a row:
f66 v13.8136
f67 v14.0461
f68 v13.5684
To make the point animation, I did these steps:
1. create a zig-zag curve
2. resample with Treat Polygons As Subdiv Curves
3. Carve sop with First U animated from 0 to 1 (constant anim curve)
4. Create point that always gets its position from point Zero of the carve curve
What should I do to get a smooth anim?
Edited by olivierth - March 4, 2024 15:55:19
Technical Discussion » Copy-To-Point : Normals are not affected [{SOLVED}]
- olivierth
- 1007 posts
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Ok, my work around was to copy grids to each point, use a normal sop to calculate prim normals and copy those grids onto my animated point. Right after that, I have a wrangle that creates a point for each grid with the prim normal as the point normals. Now all works.
I'd still like to understand why a copy-to-point behaves differently with custom wrangle-created normals than those created by a normal sop...
I'd still like to understand why a copy-to-point behaves differently with custom wrangle-created normals than those created by a normal sop...
Technical Discussion » Copy-To-Point : Normals are not affected [{SOLVED}]
- olivierth
- 1007 posts
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I created polygons from my 4 points in the hope that it would solve my problem. I still get the probleme. BUT! If I overwrite my custom normals by using a normal sop (set to point), I dont get the problem. Why would creating normals from a wrangle behave differently than using a normal sop?
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