How to use morph targets / key shapes?

Scripting Issues
1

I have a rigged model with bones and key shapes (morph targets).
The model in gltf and imported using panda3d-gltf.
I can see the “morph” line using actor.listJoints()
I have tried something like this:

np = actor.control_joint(None, 'modelRoot', '1')
np.set_x(1.0)

But panda keeps telling: “Actor(warning): Cannot control joint 1”
I even tried to use key shape names instead of index.

2

As far as I know, you need to call the egg-optchar utility to get access to the node. However it is not entirely clear how to apply this to gltf

https://docs.panda3d.org/1.10/python/programming/scene-graph/manipulating-a-piece-of-a-model

3

No, what you’re doing is correct, no egg-optchar needed. Can you share the file?

4

Made a simple example for testing:

#!/usr/bin/env python3

import sys

from direct.showbase.ShowBase import ShowBase
from direct.actor.Actor import Actor


class Demo(ShowBase):
    def __init__(self):
        super().__init__()
        self.actor = Actor('cube.glb')
        self.actor.reparent_to(self.render)
        self.actor.listJoints()

        self.morph = self.actor.control_joint(None, 'modelRoot', '1')
        self.morph.set_x(1.0)

        self.cam.set_y(-10)

        self.accept('q', sys.exit)
        self.accept('f3', self.toggleWireframe)


if __name__ == '__main__':
    demo = Demo()
    demo.run()

cube.glb (56.7 KB)
cube.blend (795.1 KB)

5

No CharacterSlider is being created for this morph. Please file this test case as a bug report on the panda3d-gltf project, thanks!

It looks like what’s happening is that panda3d-gltf is expecting the mesh to have default weights assigned, which this one doesn’t.

6

Actually, this looks like a trivial fix. I just pushed a fix to panda3d-gltf; please try the latest version.

Note that the morph is named “Test” and not “1”, so it should be accessed as “Test”.

7

It still doesn’t work. I have tried with a morph name (Test) as well.

8

It works for me with latest Git panda3d-gltf and manipulating “Test”.

Did you touch cube.glb or clear the model-cache after the update?

9

Nice. It works now. It was cached. Thanks!