Copy Rotation of (nearest empty with 'x' Property)

Game Engine Game Engine Support and Discussion
1

Ok, so:
I can copy the rotation of an object via python in BGE (thanks to you good folks;))

But, how do I:

  1. make it only copy/apply 1 axis rotation (y local for example)?
  2. only from objects that have a certain property?
  3. that is the closest out of all that have that property?

(QuestionCombo lol),
Any help you all can provide will be greatly appreciated!

Thanks :slight_smile:

2

1:


eu_own = own.worldOrientation.to_euler()
eu_target = target.worldOrientation.to_euler()
eu_own.y = eu_target.y

own.worldOrientation = eu_own

2:


objects_with_prop = [o for o in scene.objects if "prop_name" in o]

3:


dist = lambda o: (o.worldPosition - own.worldPosition).magnitude
object_distance = [(o, dist(o)) for o in objects_with_prop]
object_distance.sort(key=lambda t: t[1])
closest = object_distance[0][0]

Putting it together should be a good exercise for you.

3

Thanks for your reply Goran!
I’ve spent a few hours putting this together and debugging error messages (took me a while to figure out what each one meant, but I did it :slight_smile: ).

But I still did something wrong though, because it’s not copying the rotation. (and there is no error message telling me why)

Here is the .blend, I think maybe I did something wrong on the logic side?

(W,A,S,D to move the cube)

Attachments

copy closest rotation.blend (652 KB)

4

The file you posted does raise an error at line 19 since you left target as a list instead of a game object. You need to set target to an individual object from the list before you use target.worldOrientation.

5

YES!!! It WORKED!!!

Thank you both Goran and Mobious!!!

Here is what I did.

import bge

scene = bge.logic.getCurrentScene()
cont = bge.logic.getCurrentController()
own = cont.owner

# objects with property
objects_with_prop = [o for o in scene.objects if "CopyMe" in o]
target = objects_with_prop

# closet
dist = lambda o: (o.worldPosition - own.worldPosition).magnitude
object_distance = [(o, dist(o)) for o in objects_with_prop]
object_distance.sort(key=lambda t: t[1])
closest = object_distance[0][0]
target = closest

# copy rotation
eu_own = own.worldOrientation.to_euler()
eu_target = target.worldOrientation.to_euler()
eu_own.y = eu_target.y

Thank you two for your help!

side note: the reason I wasn’t seeing the error line was because I had multiple blend files open and I was looking at the wrong console :stuck_out_tongue:

Attachments

copy closest rotation.blend (648 KB)

6

Nice try. It seems to do some kind of something , but it’s not really working properly. It’s not doing a true copy of the closest rotation.

7

Try this one. Is this what you were trying to do ? It would be nice to interpolate between transitions.

Attachments

copy closest rotation.blend (647 KB)

8

Here is another version without the near sensor.

Attachments

copy closest rotation without near sensor.blend (145 KB)

9

Thanks blenderer2012, my file was behaving odd as a result of the Euler rotation, I changed it to quaternion and it behaved better.
Euler has this odd hate for 360 degree rotations, it can’t seem to interpret how the object should reach a particular point in rotation.

I needed to copy only one axis because I need the other axis (axises? axies?) to be influenced by other things.
So what I have now is this:


import bge

scene = bge.logic.getCurrentScene()
cont = bge.logic.getCurrentController()
own = cont.owner

# objects with property
objects_with_prop = [o for o in scene.objects if "CopyMe" in o]
target = objects_with_prop

# closet
dist = lambda o: (o.worldPosition - own.worldPosition).magnitude
object_distance = [(o, dist(o)) for o in objects_with_prop]
object_distance.sort(key=lambda t: t[1])
closest = object_distance[0][0]
target = closest

# copy rotation
eu_own = own.worldOrientation.to_quaternion()
eu_target = target.worldOrientation.to_quaternion()
eu_own.z = eu_target.z
eu_own.w = eu_target.w

own.worldOrientation = eu_own

Euler has been such a headache because it doesn’t do 360 degrees (some years ago, I screamed at my monitor in rage as I attempted to make my character spin)

Knowing this now, I don’t use Euler because it produces odd results like you saw in my blend, you guys gave me the code and I simply fit it to my needs :slight_smile: (I didn’t think to post my corrected blend lol)

Thank you for your help :slight_smile: