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Technical Discussion » Bullet physics implementation and other stuff
- Darric
- 31 posts
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Very impressed with the latest fluid video, by the way! Can't wait to play around with that.
Technical Discussion » Bullet physics implementation and other stuff
- Darric
- 31 posts
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Technical Discussion » How to export an RBD's simulation as an FBX file for Maya...
- Darric
- 31 posts
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Sure, which bit isn't working?
Use File -> Export -> FBX to pick the object you want to export, and to where, then in Maya use File -> Import to bring it in. Make sure you choose FBX as the file type, and also that the plugin is enabled in Maya.
Oh, also be sure you set a frame range in Houdini to export animation, and have a “Animation” checked in Maya to bring it in.
Is there some specific problem you're having?
Use File -> Export -> FBX to pick the object you want to export, and to where, then in Maya use File -> Import to bring it in. Make sure you choose FBX as the file type, and also that the plugin is enabled in Maya.
Oh, also be sure you set a frame range in Houdini to export animation, and have a “Animation” checked in Maya to bring it in.
Is there some specific problem you're having?
Technical Discussion » Motion blur on dops objects
- Darric
- 31 posts
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Hiya, before I address the specific problem, I figure a brief rundown of motion blur in Houdini couldn't hurt, as it's a pretty common problem:
With motion blur you generally have two options, deformation blur and velocity blur.
Deformation blur is the deafult, and it uses the subframes of your animation - so you won't be able to use it if your subframes aren't being calculated correctly, which is generally a problem if you have changing point counts. The best way to check subframes is to uncheck “Integer Frame Values” in the Global Animation Options (right of the timeline). If your point counts aren't changing, but you don't have subframes, you can create them with a TimeBlend SOP.
None of this is relevant to your problem however! The reason being that you've enabled “Geometry Velocity Blur” at the object level (under Render -> Sampling). Velocity blur doesn't use subframes, but instead relies on a velocity attribute on your geometry, which you don't have. Because this is being calculated in your dopnet, you can pull it in by using a DOP Import SOP instead of the Object Merge you're using. That way, you get the velocity attribute, and velocity motion blur will work. Alternative, you can Compute Velocity with a Trail SOP, but this has the same caveat as deformation blur, and needs consistent point counts.
Your point counts aren't changing in a simple scene like this, so either option works. Where possible you want to use deformation blur, as it's more accurate than velocity blur.
tl;dr: Uncheck “Geometry Velocity Blur” on your fetch_ball object.
Hope that helps.
With motion blur you generally have two options, deformation blur and velocity blur.
Deformation blur is the deafult, and it uses the subframes of your animation - so you won't be able to use it if your subframes aren't being calculated correctly, which is generally a problem if you have changing point counts. The best way to check subframes is to uncheck “Integer Frame Values” in the Global Animation Options (right of the timeline). If your point counts aren't changing, but you don't have subframes, you can create them with a TimeBlend SOP.
None of this is relevant to your problem however! The reason being that you've enabled “Geometry Velocity Blur” at the object level (under Render -> Sampling). Velocity blur doesn't use subframes, but instead relies on a velocity attribute on your geometry, which you don't have. Because this is being calculated in your dopnet, you can pull it in by using a DOP Import SOP instead of the Object Merge you're using. That way, you get the velocity attribute, and velocity motion blur will work. Alternative, you can Compute Velocity with a Trail SOP, but this has the same caveat as deformation blur, and needs consistent point counts.
Your point counts aren't changing in a simple scene like this, so either option works. Where possible you want to use deformation blur, as it's more accurate than velocity blur.
tl;dr: Uncheck “Geometry Velocity Blur” on your fetch_ball object.
Hope that helps.
Technical Discussion » phyllotaxis and plants in Houdini– How to?
- Darric
- 31 posts
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Bear in mind that when you're seeing nodes with parameters that are seemingly unavailable in Houdini, it's most likely because ptakun built a whole whack of digital assets to facilitate his incredible creations.
On a side note, I came to Houdini with an interest in proceduralism and L-systems, so discovering ptakun's work was one of my big inspirations for wanting to learn the software. Almost four years on, and it's still one of the best examples of the power of Houdini's approach.
On a side note, I came to Houdini with an interest in proceduralism and L-systems, so discovering ptakun's work was one of my big inspirations for wanting to learn the software. Almost four years on, and it's still one of the best examples of the power of Houdini's approach.
Technical Discussion » Exporting Pathed Cameras
- Darric
- 31 posts
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First time I've had to look at it since I asked, but yeah, the Object node was exactly the magic trick I was looking for.
Thanks, all.
Thanks, all.
Technical Discussion » Exporting Pathed Cameras
- Darric
- 31 posts
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Thanks guys for the responses, apologies for the late follow-up. I've been doing other projects meanwhile, and just remembered that I posted this thread! ><
As soon as I get a chance to get back to it, I'll let you know how it works out.
As soon as I get a chance to get back to it, I'll let you know how it works out.
Technical Discussion » Exporting Pathed Cameras
- Darric
- 31 posts
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Hi there,
We use Houdini's .clip file format as our standard for exported cameras, and have a number of minor plugins to handle this format for importing and exporting into other 3d packages. For the most part, our cameras only ever come from matchmoving software or from the animation package (in this case XSI) but I'm trying to create a simple OTL in the rare event that a camera has been animated in Houdini, and needs to be exported as a .clip.
Fetching the data channels (tx,ty,tz,rx,ry,rz,aspect,aperture,focal,resx,resy) and calling opsave to write out the .clip is simplicity itself, but fails in the case of a camera which is animated along a path, or has a Look At specified, due to the transformation information not being present in the data channels.
What is the simplest method for extracting the actual internal transformation of a camera, in the case that this information is not present in the t,r channels? I've tried searching the HOM documentation, to no avail, but I'm not discounting that I might just not be seeing what is in fact there.
Thanks in advance.
We use Houdini's .clip file format as our standard for exported cameras, and have a number of minor plugins to handle this format for importing and exporting into other 3d packages. For the most part, our cameras only ever come from matchmoving software or from the animation package (in this case XSI) but I'm trying to create a simple OTL in the rare event that a camera has been animated in Houdini, and needs to be exported as a .clip.
Fetching the data channels (tx,ty,tz,rx,ry,rz,aspect,aperture,focal,resx,resy) and calling opsave to write out the .clip is simplicity itself, but fails in the case of a camera which is animated along a path, or has a Look At specified, due to the transformation information not being present in the data channels.
What is the simplest method for extracting the actual internal transformation of a camera, in the case that this information is not present in the t,r channels? I've tried searching the HOM documentation, to no avail, but I'm not discounting that I might just not be seeing what is in fact there.
Thanks in advance.
Houdini Lounge » How to render nice looking fluids?
- Darric
- 31 posts
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