Just a guy, drifting.
Posts tagged Houdini
VOP COP Raster Depths
Sep 10th
This was an odd video to do since it seems to be a simple topic but when talking about it out loud it starts sounding complicated. I’m basically covering several sub-topics which support the overall topic. Despite the confusing ramblings in the video, what you should take away from it is that in VOP COPs, the “Raster Depth” setting can cause results to vary depending on the data generated inside.
The hip file I’m using is actually based on a workshop that used to be online (but doesn’t appear to be anymore). I used it because it had the exact components to demonstrate everything.
Also, I’m sure my friend Jason will say that he is in no way regal when it comes to compositing, but seeing what he’s been up to lately certainly indicates that he knows what he’s doing 
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Sprites On Points Digital Assest
Jun 12th
Sprites are pretty cool, but in a clean install of Houdini you can only use them on particles using the Sprite POP. It turns out, you can add some attribute trickery to make sprites work on plain ol’ points. The cooler thing is that this Sprite SOP concept works in Houdini Escape (which doesn’t have particles). I wrote a full blown help for it too, with an icon and all – which basically copies the Sprite POP language and replaces “particles” with “points”. Yes, this has been done before. But let’s face it – that one’s old.
You can find it on my Houdini page or you can get the asset directly from here.
For those interested, here are the attributes you need to get sprites on points:
- spriterot: class: point, type: float, size: 1
- spritescale: class: point, type: float, size: 2
- spriteuv: class: point, type: float, size: 4 (spriteuv[0] = U-offset; spriteuv[1] = V-offset; spriteuv[2] = U-scale; spriteuv[3] = V-scale)
- spriteshop: class: point, type: string
Varying Materials Using A Single Shader
May 24th
Nothing ground breaking here, but for someone who is into neat little tricks to control shaders, I thought this was worth showing. What the video covers is a way to vary the materials on a single object using a single shader (differing from the usual method of using multiple shaders for different pieces of an object). I’ll leave it at that and let the video do the talking. I’m starting to record at my screen’s native resolution (1680 x 1050) which ups the video size but I like seeing big videos. I’m also posting these on Vimeo which I think is nice to have since you’re not always on a machine that you can download videos on.
Note: Video re-done on 5/25/2009. I thought it could be cleaner and more focused on production nuances so I re-recorded it.
Houdini Python COM Conclusion
Apr 28th
After getting something working, and continuing off and on with trying to get it to work, I have come to develop some concepts about using a Python COM method to poll 3DConnexion data.
- The operators at the geometry level (the Python operator and Script SOP) are unable to poll the data. This seems to be due to cooking issues as well as the geometry operators using the hou module only to create/manipulate data.
- The operator at the object level (the Python operator) does poll the data, however it seems that this polling becomes the dominant process in Houdini and you can do nothing else or stop the polling.
So the conlcusion that can be drawn is that the Python COM method for polling data is not a viable one. The idea of having Houdini write the values of the device to certain parameters and see the results in real-time just doesn’t seem to work. It is certainly possible I am overlooking something however I’ve spent a lot of time on this and with a working and better alternative out there now there isn’t a pressing need to continue. This project has helped me learn a lot about Python in Houdini as well as the common object model so the effort wasn’t entirely without gain. Now it’s time to move on and continue to learn more about Houdini!
Houdini And 3DConnexion Devices
Apr 11th
Yes – I have something working! Read on for the story and where I’m at:
I’ve noticed a problem with a lot of animated shorts and student work: The camera work is atrocious. It seems like all the time is spent on perfecting the modeling, animation, and shading, then in the last 10 minutes of production someone puts in a camera and animates it going to the left. Seeing this as a major issue I thought that there must be a better way to have the camera animated easily and a whole lot better. I then recalled I had a 3DConnexion SpaceNavigator that I never use because no applications I use support it. The whole line of 3DConnexion devices might be just what animators need to have better control of their camera. More >
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