30 January 2012 Previous

Voodoo, Blender 2.5 and rotoBezier

After seeing Blender's new rotoBezier plugin, I couldn't resist test-driving it.  This little demonstration shows a tracking and masking masking workflow using Voodoo, Blender 2.5 and the new rotoBezier plugin.

I was pleasantly suprised to see that Voodoo had an exporter for a blender 2.5 script.  It must have been written way back when the API was rather unstable as it doesn't run off the bat, but a quick fix will sort it out.  To be noted is that the export for a 'free' camera does not work and the camera has to be 'rotating on a stand' when the footage is first opened into Voodoo.  The camera data seems to be rather accurate in voodoo, but sometimes appears a little thrown out when exported to Blender . - which is where the new rotoBezier plugin comes in to help make corrections

Download the blend here from blendswap
Martin Lindelöf notes below about libmv, which aims for camera tracking in Blender, he mentions the following insanely cool links: http://www.youtube.com/watch?v=dBT5d6ndmuQ and one with Suzanne: http://www.youtube.com/watch?v=hswISipCv2M&feature=related

When in Blender, after setting the background image to a video of the footage, the camera movement appears to not entirely match up.  I'm not sure if this has to do with the video footage itself or the type of camera from Voodoo.

Anyway, in comes the rotoscoping plugin and we can correct the misalignments nice and quickly, it's a great workflow improvement.  It does however feel a little awkward masking a 2D plane from a camera in the 3D view, it's a little tricky to zoom in and out as you have to use the mouse scroll-wheel (which i don't have).  I find that when viewing the scene in the video sequence editor, the scene strip doesn't always an image strip of the footage.  I didn't look into it with too much detail, but here are two images to show the differences on frame 7: (note the amount of sky showing through in the second image)

3d Viewport frame 7 Sequence Editor view, frame 7

I would be keen to hear about other open camera tracking software too.

Getting Voodoo's 2.5 .py export to work in 2.5

One can always export it for 2.4, create the scene in 2.4 and then open it in 2.5, but it's not too hard to get the script to work straight in 2.5.  The video demonstrates this.  If the text is too hard to read, it can be taken from here instead:

 EDIT: the previous python code was removed as it was no longer functional.  Boris has posted a nice flash tool to convert the script into a workable format.  I'm unsure if it's still valid for newer versions of Blender and will need to be tested.  The fall back method of exporting the Blender 2.4 python script from Voodoo; loading that into Blender 2.49; running the script and saving the .blend file; then opening the saved .blend in a newer Blender 2.5x version. should ideally work.

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