Grow collision shape without getting physics stuck.

zerohootsoliver

Is there a way to grow collision shapes? For example, to create an explosion. I tried using an AnimationPlayer, executing each frame on the physics process mode. How do I make this work without problems like going through walls and other unexpected behavior.

Erich_L

If it's an explosion you're after, instead of changing the size of a collision shape rapidly to push thing away (I assume that's what you meant), a better solution might be just to use an area node to get all the objects within the range of the explosion then do a little math to see in which direction (vector from the source of explosion) you can add explosive force. It direction of course will be different for each object and you could also change force based on distance from explosion.

zerohootsoliver

@Erich_L said: If it's an explosion you're after, instead of changing the size of a collision shape rapidly to push thing away (I assume that's what you meant), a better solution might be just to use an area node to get all the objects within the range of the explosion then do a little math to see in which direction (vector from the source of explosion) you can add explosive force. It direction of course will be different for each object and you could also change force based on distance from explosion.

Glad you understood what I meant. I did read into other techniques and this sounds like the simplest way.

cybereality

So @Erich_L gave you the correct solution, but just so you can understand, collision shapes are generally not to be modified at run-time. You cannot change their scale without messing up the physics engine. They are treated similar to rigid bodies, and their shape cannot change. When you do this, the physics engine attempts to recalculate the shape, but it usually fails, and if anything is touching the object the collisions become totally incorrect. So you should never scale them.