ManimCommunity / ManimCommunity/manim
[BUG] add_updater does not work when redering with OpenGL.
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Description
## Description of bug / unexpected behavior
add_updater does not work when redering with OpenGL. The code runs normally under the Cairo renderer.
Code for reproducing the problem
```py
class BugReport(Scene):
def construct(self):
wave_generate = Circle(radius=0.3, color=RED_A, fill_color=BLUE, fill_opacity=0.3,
stroke_width=0.8).move_to(3 * LEFT)
Nc = 20
circle_list = [Circle(radius=0.3 + 0.8 * i, color=RED_A, stroke_width=1).move_to(3 * LEFT) for i in range(Nc)]
self.add(wave_generate, *circle_list)
self.wait(1)
self.remove(wave_generate, *circle_list)
self.start_time_for_circle = self.renderer.time
def circle_update(mob, phase):
v_factor = 1.5
current_time = self.renderer.time - self.start_time_for_circle
radius = math.fmod(0.8 * phase + v_factor * current_time, 0.8 * Nc) + 0.3
mob.set(width=2 * radius)
if radius - 0.3 <= v_factor * 1.1 / self.camera.frame_rate:
mob.set_x(wave_generate.get_x())
update_list = []
for i in range(Nc):
update_list.append(lambda mob, phase=i: circle_update(mob, phase))
(circle_list[i]).add_updater(update_list[i])
self.add(wave_generate, *circle_list)
self.wait(2)
self.play(wave_generate.animate.shift(5 * RIGHT), run_time=5, rate_func=linear)
for i in range(Nc):
(circle_list[i]).remove_updater(update_list[i])
self.wait(2)
```
Cairo:
https://github.com/user-attachments/assets/8ee0193b-66e1-4320-b4eb-c4674ac7f17f
OpenGL:
https://github.com/user-attachments/assets/f7d43e46-69f7-4037-acac-3d10c2ee41a9
## System specifications
System Details
- OS Windows 11
- RAM: 64GB
- Python version : Python 3.10
LaTeX details
+ LaTeX distribution: TeX Live 2024
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by running the provided BugReport reproduction under both the Cairo and OpenGL renderers on the listed Python and Windows setup. Compare how the add_updater callbacks affect the circles, then trace the renderer-specific update path. Done means the animation behaves consistently with Cairo when rendered with OpenGL.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- computer-graphics
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100