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Issues importing camera tracking data from blender

Hi all,

I am using Blender to track the camera movement data, then exporting the data and reading it in vvvv to create real-time animations matching the background video footage. Already tried with voodoo but the tracking data wasn’t so effective, quick and precise as the one in blender 2.8.

So, since I have not found much info online on how export simple camera data from Blender, I tried some exporters and found the one for Nuke (.chan) could work.
This Nuke exporter writes the following columns per each camera animation frame:
frame location.x location.y location.z rotation_euler.x rotation_euler.y rotation_euler.z angle_y

I have tried to build a template patch in vvvv (here attached the whole package) with tracked footage and 3D placeholders. My limited knowledge in matrix transformations do not let me proceed. I copied some nodes from the voodoo patch but it did not work. Something wrong with the rotations.

Thanks.

hey ddf,

you’ve got quite a few things going on there already with transformations which makes it hard to understand, follow and give advice. try to reduce this to the most minimal setup possible. remove all transformations. only loading the reference file and visualizing the cameras position path (ignore rotation for a start) should already be meaningful if you get coordinate systems right. this doesn’t seem to be the case to me…

just a hint, blender uses a different coordinate system convention than vvvv beta/directx.

Thanks for your replies,
in the meanwhile I tried to to work with fbx and assimp, maybe there could be more audience. So far no success to me.
Please see attached a v4p file that illustrate the process followed in importing camera. Hope this is clearer for you to understand where I am not proceeding correctly.
Thanks a lot for your help

BLENDER TO VVVV ASSIMP CAMERA ISSUES.zip (278.7 KB)

the blender camera rotation is always wrong. so you have to rotate it in the right direction. Also its really helpful to use the projector node to debug. for the fov settings: i just matched it by hand.

image
assimp attempt.v4p (45.2 KB)

Thanks jj-h. All working fine in this way even with camera rotations (see this new fbx). Attached here a clean version with a module fbx in and camera transforms out pins ASSIMP ATTEMPT OK.zip (35.8 KB)
Cheers