Blender exporter with animation
michaeleggers opened this issue · 4 comments
Hi and happy new year!
I have written a blender exporter that writes out .gpmesh, .gpskel and .gpanim(s) These are the custom file formats in the book from chapter 12 on.
When loading the files in the engine (I used chapter 12) the gpmesh comes in fine, the tpose is correct but the other
animations are messed up. You can still see the animation matches somewhat the one created in blender but something is wrong there. I was not able to figure out where the mistake happens. To my best knowledge the skeleton and animation files contain the
local transforms of the bones using matrix_local in Blender's python API.
I included the script and the example Blend file (Blender 3.0.0) for testing in my fork: https://github.com/michaeleggers/code/tree/blender-exporter-update/Exporter/Blender
Maybe someone is interested in looking into it.
As I am relatively new to Blender, I used this tutorial to model, rig and animate and also used the texture provided by Imphenzia:
https://youtu.be/yjjLD3h3yRc
The exporter works now. The reason it did not work is that you manually have to calculate the bone's local transformation by hand. When doing the calculation the matrix-multiplication is done by operator @ and not *, which does a component-wise multiplication!!! Wasted some time on that as I was not familiar enough with mathutils which is the math lib used by Blender Python API. Also, the quaternions have to be inverted. I am not sure why, though. It was intuition after a lot of trial and error.
To export:
- make sure the armatures pivot is the same as the model's pivot it is attached to.
- at the moment there have to be at least two keyframes for an animation if you decide to export it.
- select the model in object mode and then go to file -> export -> gpmesh.
Exported UV's are incorrect at the moment. About to fix that.
This is really cool! Well done.
Thank you! I am going to fix the UVs and then going to open a PR if that's okay.
Opened a PR: #48