Hi everyone. I decided to post my question in this forum due to all the power users that are chiming in here. I“m currently using Houdini and Modo to render a massive amount of Marbles rolling down a ramp. I'm a power Houdini guy and my lighting team is working in Modo.
We've had amazingly good luck passing a big particle set from Houdini to Modo using Alembic. It's fast & efficient and best of all the velocity vectors seem to come across successfully. I was sceptical because the particles are emitting throughout the shot and the point count is changing. I thought that was going to be an issue but it didn't seem to be.
What is a problem is rotations. The balls need to roll but they're not reorienting in Modo. Does anyone know if an attribute of some kind can help with this? I have the ”orient" attribute on export from Houdini but I have no way of knowing if that is successfully making it across or if it is what Modo would need.
Any help with this would be appreciated. Thank you!
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SI Users » The Houdini Modo combo
- freejonah
- 37 posts
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Technical Discussion » 6 Axis Robot Arm using IK
- freejonah
- 37 posts
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I'm looking for a good solution for creating an IK rig that behaves like a 6 axis robot arm like one would see in a modern car factory. This means each rotation axis would be heavily constrained to it's own rotation axis.
My target that the rig will follow is a matchmove so it needs to follow it exactly. In theory a six degree robot should be able to follow any point in space, but the math escapes me right now. Have any of you done something like this? Curious to see what's been done in the community.
Thanks in advance,
Jonah
My target that the rig will follow is a matchmove so it needs to follow it exactly. In theory a six degree robot should be able to follow any point in space, but the math escapes me right now. Have any of you done something like this? Curious to see what's been done in the community.
Thanks in advance,
Jonah
Houdini Lounge » Looking for floating object ideas
- freejonah
- 37 posts
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Genius Houdini Community!
I'm having a hard time wrapping my head around something so I thought it best to ask the experts out there.
We're about to do a project where a rigid object ( like a box or a tea kettle ) is floating weightlessly in a room. It is being blown around by wind and bumping into objects as it goes. What we would like to do is loosely keyframe the object for basic choreography and timing but have the dynamic object “follow” it, like a target. This way you get the benefit of having keyframed motion influencing the dynamics.
Would a sop solver be the right way to go here? Field force? It's been a while since I used dops so any advice or examples would be appreciated. I'm sure there's an elegant solution out there but I'm just not able to think of it.
Thanks very much!
I'm having a hard time wrapping my head around something so I thought it best to ask the experts out there.
We're about to do a project where a rigid object ( like a box or a tea kettle ) is floating weightlessly in a room. It is being blown around by wind and bumping into objects as it goes. What we would like to do is loosely keyframe the object for basic choreography and timing but have the dynamic object “follow” it, like a target. This way you get the benefit of having keyframed motion influencing the dynamics.
Would a sop solver be the right way to go here? Field force? It's been a while since I used dops so any advice or examples would be appreciated. I'm sure there's an elegant solution out there but I'm just not able to think of it.
Thanks very much!
Technical Discussion » Wheel Rotate based on distance
- freejonah
- 37 posts
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Hi everyone. I stumbled on this thread and was wondering if you've tried using the Area Chop. It's my go-to node for measure distance. Usually I use a trail sop ( like Antoinne did ) but I only trail it for one frame. I measure t he distance between current and previous frame. Then I store that in an attribute that I pull into chops using a geometry chop. Following that with an area chop gives me a cumulative distance traveled between whatever frame range you choose.
hope this helps.
jonah
hope this helps.
jonah
Houdini Lounge » .max, .3ds and others file formats
- freejonah
- 37 posts
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I just spent some time doing what I always do at my job where I work as a Visual Effects Supervisor. I trawl the internet for models relevant to the movie or tv commercial I'm working on.
I always have a lump in my throat when I see all those tons of models in either .3ds or .max format that I have no hope of reading into houdini. Why is this? Shouldn't this be a simple conversion? It still reads in .iges, .dxf and .rib, relatively obscure formats for model exchange. Why not let us read in the format that just about all models are stored in? Thank god we have a license of Maya around so we can convert those to .fbx or obj.
Please please add more file types to geometry import! thanks.
I always have a lump in my throat when I see all those tons of models in either .3ds or .max format that I have no hope of reading into houdini. Why is this? Shouldn't this be a simple conversion? It still reads in .iges, .dxf and .rib, relatively obscure formats for model exchange. Why not let us read in the format that just about all models are stored in? Thank god we have a license of Maya around so we can convert those to .fbx or obj.
Please please add more file types to geometry import! thanks.
Technical Discussion » arbitrary camera_NDC space in shader?
- freejonah
- 37 posts
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that's what i figured. Pixel aspect.
I'm curious about this null RIB output thing, though? Why can't they put that into other objects like a camera or geometry? My operator is a little annoying in that it requires me to parent a null to a camera and then reference both of them in my shader. I would love to just give it the name of a camera or a light and let 'er fly.
I submitted an RFE to sidefx regarding this.
thanks so much for your help, Mario
Jonah Hall
Public Visual Effects
Venice, CA
I'm curious about this null RIB output thing, though? Why can't they put that into other objects like a camera or geometry? My operator is a little annoying in that it requires me to parent a null to a camera and then reference both of them in my shader. I would love to just give it the name of a camera or a light and let 'er fly.
I submitted an RFE to sidefx regarding this.
thanks so much for your help, Mario
Jonah Hall
Public Visual Effects
Venice, CA
Technical Discussion » arbitrary camera_NDC space in shader?
- freejonah
- 37 posts
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This seems to work nicely, Mario. Thank you. What's even nicer is that I can easily parent the null object to the camera and use it's wiring to grab all the camera viewing parameters.
One question, though: device aspect is not the resx/resy ratio, but the pixel aspect? The reason I ask is that this little doohicky works when i set the aspect to 1 regardless of my resolution values.
Just wondering. Otherwise it's a charm. Thanks.
One question, though: device aspect is not the resx/resy ratio, but the pixel aspect? The reason I ask is that this little doohicky works when i set the aspect to 1 regardless of my resolution values.
Just wondering. Otherwise it's a charm. Thanks.
Technical Discussion » arbitrary camera_NDC space in shader?
- freejonah
- 37 posts
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Very nice. I can wrap this into an operator easily. Thank you.
Would the folks at Sidefx mind putting together a little Vex operator that does this very thing? It sounds like it would be pretty useful.
Would the folks at Sidefx mind putting together a little Vex operator that does this very thing? It sounds like it would be pretty useful.
Technical Discussion » arbitrary camera_NDC space in shader?
- freejonah
- 37 posts
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HI there,
Sometimes I find myself doing projects with lots and lots of prebaked geometry data that is a hassle to go back and recook. In these cases I really wish I could tell my surface shader to look up some coordinates from a projection camera ( OTHER than my rendering camera ) that I've set up without having to go back and bake in UV coordinates on the points or vertices. I see that you can do something in Light_NDC space, which is cool. I would like to do the same transform in a camera_NDC space.
Sometimes I find myself doing projects with lots and lots of prebaked geometry data that is a hassle to go back and recook. In these cases I really wish I could tell my surface shader to look up some coordinates from a projection camera ( OTHER than my rendering camera ) that I've set up without having to go back and bake in UV coordinates on the points or vertices. I see that you can do something in Light_NDC space, which is cool. I would like to do the same transform in a camera_NDC space.
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
- Offline
no, no resultion so far. I'm about to install a new houdini and try it again. I'll let you know what happens.
Technical Discussion » Sculpting animated volumes
- freejonah
- 37 posts
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This is very very helpful. Thanks so much for taking the time to put this together for me.
In the event of rotating the points, how would that work? Also, does the point cloud lookup treat them like metaballs, interpolating the values?
In the event of rotating the points, how would that work? Also, does the point cloud lookup treat them like metaballs, interpolating the values?
Technical Discussion » Sculpting animated volumes
- freejonah
- 37 posts
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Here is a hip file and a quicktime showing what sort of thing I'm working on. Let me know if you guys have a better way of doing this sort of thing.
Technical Discussion » Sculpting animated volumes
- freejonah
- 37 posts
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You're not off base at all. Obviously that sort of thing is working fine. The issue is finding ways to get more information out of the input geometry than density, particularly some kind of volumetric uv set to go with it. The problem is largely animated objects and trying to use the noisy volume stuff as a texture map. If you model an animated object and run isoffset on it, you can get either a constant density field ( fog ) or a nice distance to edge field ( SDF ). Those are great, but what I would like is a way to grab a uv, rest or some other parametric value from that object and turn it into a nice lookup table to generate noise off of that follows the object.
The particular problem I'm working on has to do with carrying uv coordinates through the volume system all the way to the renderer. Essentially I'm trying to get “P” out of my noise generating at the shader level by replacing it with something that deforms with the geometry. Imagine an animated guy walking across the scene. I'm trying to fill him with puffy cloud stuff without having the noise pass through him. I want the noise to move with his body, as if he he's made of big shaggy carpet stuff.
I started experimenting with creating a “uvw” volume, and it's been really good! The tricky bit is stuffing coordinate values into a volume that doesn't really know that the stuff around it is moving. Currently I'm stuffing a block of points with uv values that relate to the geometry nearest to it, then source those uvw values from a volumemix node using nearpoint() followed by a point() expression. I then including these four volumes at render time:
o: density
1: uv.x
2: uv.y
3: uv.z
this does a nice job of “gluing” the coordinates the shader uses to the volume at render time. I would really like to use the volumevop to do this but I'm not sure how to use the pointcloud stuff yet. Those vop nodes don't have help cards, unfortunately ( RFE! ).
The particular problem I'm working on has to do with carrying uv coordinates through the volume system all the way to the renderer. Essentially I'm trying to get “P” out of my noise generating at the shader level by replacing it with something that deforms with the geometry. Imagine an animated guy walking across the scene. I'm trying to fill him with puffy cloud stuff without having the noise pass through him. I want the noise to move with his body, as if he he's made of big shaggy carpet stuff.
I started experimenting with creating a “uvw” volume, and it's been really good! The tricky bit is stuffing coordinate values into a volume that doesn't really know that the stuff around it is moving. Currently I'm stuffing a block of points with uv values that relate to the geometry nearest to it, then source those uvw values from a volumemix node using nearpoint() followed by a point() expression. I then including these four volumes at render time:
o: density
1: uv.x
2: uv.y
3: uv.z
this does a nice job of “gluing” the coordinates the shader uses to the volume at render time. I would really like to use the volumevop to do this but I'm not sure how to use the pointcloud stuff yet. Those vop nodes don't have help cards, unfortunately ( RFE! ).
Technical Discussion » Sculpting animated volumes
- freejonah
- 37 posts
- Offline
Hello Houdini community,
I've begun really digging into the volume tools in Houdini and am looking for some tips on sculpting volumes. I've been playing with IsoOffset, metaballs and other things. The rendering aspects of volumes feel very nice, and I'm getting good results. The shader writing is simple enough, and I'm doing fine there too. It's actually modeling and animating them that seems to have me a bit stumped ( granted I've only been doing this for 1 day. )
What I'm trying to do is figure out how to really use sops to have good control over density modeling and managing the rest position that the shaders use to build noise and other rendertime attributes. Some basic questions:
1. How can you use a rest position with a metaball? Will it transform correctly?
2. How do you control density so that it falls off gradually towards the volume's boundary, rather than just butting up against the edge?
3. Can we use surface meshes to build volumes where the uv, rest or some other coordinate drives the look and feel of the volume?
4. Is it expected that we fill an empty volume with density values from points and other primitives? If so, how is this done?
5. Are there ways to offset density values in the volume primitive, rather than multiplying them? Dropping noise values down below 0 around the edges always gives you those nice wispy effects. I would love to have that option.
Sorry if these questions are a bit broad. I'm used to being able to use sops to build very specific geometry but I'm feeling like the volumes are a bit of a black box right now. I'm willing to bet I just don't have an understanding of it yet.
I, of course, would love to see some hip files that people have that demonstrate some of these abilities. Any help would be GREATLY appreciated.
Many many thanks in advance,
jonah
I've begun really digging into the volume tools in Houdini and am looking for some tips on sculpting volumes. I've been playing with IsoOffset, metaballs and other things. The rendering aspects of volumes feel very nice, and I'm getting good results. The shader writing is simple enough, and I'm doing fine there too. It's actually modeling and animating them that seems to have me a bit stumped ( granted I've only been doing this for 1 day. )
What I'm trying to do is figure out how to really use sops to have good control over density modeling and managing the rest position that the shaders use to build noise and other rendertime attributes. Some basic questions:
1. How can you use a rest position with a metaball? Will it transform correctly?
2. How do you control density so that it falls off gradually towards the volume's boundary, rather than just butting up against the edge?
3. Can we use surface meshes to build volumes where the uv, rest or some other coordinate drives the look and feel of the volume?
4. Is it expected that we fill an empty volume with density values from points and other primitives? If so, how is this done?
5. Are there ways to offset density values in the volume primitive, rather than multiplying them? Dropping noise values down below 0 around the edges always gives you those nice wispy effects. I would love to have that option.
Sorry if these questions are a bit broad. I'm used to being able to use sops to build very specific geometry but I'm feeling like the volumes are a bit of a black box right now. I'm willing to bet I just don't have an understanding of it yet.
I, of course, would love to see some hip files that people have that demonstrate some of these abilities. Any help would be GREATLY appreciated.
Many many thanks in advance,
jonah
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
- Offline
I'm confused. I downloaded the 32bit version of houdini 10, but you're telling me that you can't use this at all now? Can somebody confirm this for me?
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
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I have been using houdini 9.5 on Ubuntu 8 just fine on my machine. Has this changed now?
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
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The good news is you were right! Thank you. I feel a little silly. I'm usually pretty good at making sure of that sort of thing, but the Ubuntu selection was sitting up on top all alone and I just grabbed it without thinking.
Now for the bad news. When I run houdini my SCREEN GOES BLACK. I have to hit the power button and restart my computer. The mouse was moving around fine and I could tell it was rolling over stuff that was still active on my desktop. I have a Macbook Pro ( 32 bit ) with dual boot. I have no idea what to do.
Just for laughs I tried moving the hsvg folder out of the way as was mentioned earlier.
any suggestions would be great.
Thanks
Jonah
Now for the bad news. When I run houdini my SCREEN GOES BLACK. I have to hit the power button and restart my computer. The mouse was moving around fine and I could tell it was rolling over stuff that was still active on my desktop. I have a Macbook Pro ( 32 bit ) with dual boot. I have no idea what to do.
Just for laughs I tried moving the hsvg folder out of the way as was mentioned earlier.
any suggestions would be great.
Thanks
Jonah
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
- Offline
this is what i get when i try to run houdini in a shell
/opt/hfs10.0.465/bin/houdini: line 8: /opt/hfs10.0.465/bin/houdini-bin: cannot execute binary file
/opt/hfs10.0.465/bin/houdini: line 8: /opt/hfs10.0.465/bin/houdini-bin: Success
/opt/hfs10.0.465/bin/houdini: line 8: /opt/hfs10.0.465/bin/houdini-bin: cannot execute binary file
/opt/hfs10.0.465/bin/houdini: line 8: /opt/hfs10.0.465/bin/houdini-bin: Success
Houdini Lounge » Ubuntu 9.1
- freejonah
- 37 posts
- Offline
Hi all,
I feel like I just showed up late to a party. Ok, I just upgraded from Ubuntu 8 to Ubuntu 9.10. I then tried to install houdini10.0.465 for Ubuntu 9.04. Install went fine, but it won't run the binary file.
I've been pointed to this thread since I started having problems. Can we assume this is the same issue you have all been having? Is it hopeless, or can I try one of these quick fixes you were talking about last month. Has there been any developments since then?
Please let me know. Also, if necessary, what's the easiest way to downgrade to Ubuntu 9.04? They make it very easy to upgrade, but it's hard to figure out how to go the other way.
many thanks
Jonah in Venice
I feel like I just showed up late to a party. Ok, I just upgraded from Ubuntu 8 to Ubuntu 9.10. I then tried to install houdini10.0.465 for Ubuntu 9.04. Install went fine, but it won't run the binary file.
I've been pointed to this thread since I started having problems. Can we assume this is the same issue you have all been having? Is it hopeless, or can I try one of these quick fixes you were talking about last month. Has there been any developments since then?
Please let me know. Also, if necessary, what's the easiest way to downgrade to Ubuntu 9.04? They make it very easy to upgrade, but it's hard to figure out how to go the other way.
many thanks
Jonah in Venice
Houdini Lounge » Houdini in Ubuntu 9.10 ?
- freejonah
- 37 posts
- Offline
Did I make a mistake?
I got very excited about the latest Ubuntu release 9.10 and installed it on my Macbook Pro ( dual boot. ). I downloaded and installed houdini apprentice for Ubuntu 9.04. Am I correct in realizing that this won't work? The intall went ok, and I can source the proper setup file. I just can't launch the binary executable.
whoops,
jonah
p.s. how long until we get an install for Ubuntu 9.10?
I got very excited about the latest Ubuntu release 9.10 and installed it on my Macbook Pro ( dual boot. ). I downloaded and installed houdini apprentice for Ubuntu 9.04. Am I correct in realizing that this won't work? The intall went ok, and I can source the proper setup file. I just can't launch the binary executable.
whoops,
jonah
p.s. how long until we get an install for Ubuntu 9.10?
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