Scenes & motion

The rendered excerpts use docs_examples.py. Its ubiquitin() helper loads PDB 1UBQ, and frame() adds the model and sets the camera. Run each excerpt inside construct(); the full script includes the imports and setup. Run the full script from a repository checkout, which includes the input structures.

p = ubiquitin()
frame(self, p)
self.play(FadeIn(p), run_time=1)
self.play(Rotate(p, np.pi), run_time=3)
self.play(Representation(p, "ribbon"), run_time=1)
self.play(
    p.animate.shift((5, 0, 0)),
    self.camera.animate.orbit(theta=0.6),
    run_time=2,
)
self.wait(0.5)

Angles are in radians. Coordinates and radii are in ångströms. Motion and morphs use quintic smooth easing by default. PlayTrajectory uses linear for a constant playback rate.

Set rate_func on play() to change easing for the call. BackboneMorph uses motion_easing instead, so residue delays keep their duration in seconds.

Animations in one play() call run together for run_time seconds. Consecutive calls run in sequence. You can combine movement with a shape change. Two concurrent animations that change the same property raise an error.

Representations#

p = ubiquitin().surface(resolution=0.7).cartoon()
frame(self, p)
self.wait(1)
for name in ("ribbon", "ball_and_stick", "surface"):
    self.play(Representation(p, name), run_time=1.2)
    self.play(Rotate(p, 0.45), run_time=1.5)

Set topology, colors, radii, and camera framing before the first play() or wait(). Use animations for later changes. Representation changes the cartoon or ribbon shape and crossfades when switching to atoms or a surface.

Fades use weighted blended transparency. Overlapping transparent objects have approximate depth ordering; see rendering for details. Ball-and-stick models use element colors. Cartoon and ribbon models accept secondary-structure, chain, rainbow, or fixed colors.

Set the camera frame explicitly. For portrait output, include the scene aspect ratio: self.camera.frame(p, margin=1.25, aspect=self.width/self.height). Region tracking can keep a moving selection centered.

Protein rotations use the molecular centroid. Camera orbits use the camera target.