Trying to add a box with create_box, unknown Value error

Question

I'm trying to add a box to a space, here's what I have:

body = pymunk.Body()
body.position = 300, 200
box = pymunk.Poly.create_box(body, (100, 300))
space.add(body, box)

I get the following error:

  File "C:\Users\Home\AppData\Roaming\Python\Python36\site-packages\pymunk\pygame_util.py", line 153, in <listcomp>
    ps = [to_pygame(v, self.surface) for v in verts]
  File "C:\Users\Home\AppData\Roaming\Python\Python36\site-packages\pymunk\pygame_util.py", line 183, in to_pygame
    return int(p[0]), surface.get_height()-int(p[1])
ValueError: cannot convert float NaN to integer

If I do not add the body in space.add, I don't get the error, but then it doesn't behave properly.

It seems p[ ] is a vertex, but since I'm using create_box, I'm not specifying any vertices.

I'm very new to pymunk, and mostly new to python, so it's likely something very simple, but I've been at it for several hours and can't crack it.

score 4 · Answer 1 · answered Nov 05 '19 at 07:21

4

Looks like I needed to add a moment to the body, this solved the problem. I previously had a mass and no moment, assuming that defaulting to value 0 as shown in the documentation would not be problematic.

answered Nov 05 '19 at 07:21

GTS

71
3

Maybe the docs should be more clear, but the reason why it defaults to 0 is that you can postpone setting mass and/or moment until later, or set it on the shapes attached to body. – viblo Nov 06 '19 at 11:54
@viblo That makes sense to me. Thank you. – GTS Nov 07 '19 at 00:29
adding moment to static body makes it fall, any help ? – Prajjwal Pathak Nov 27 '22 at 18:10

Trying to add a box with create_box, unknown Value error

1 Answers1