Collisions on objects in display groups

Solar2D General Questions/Discussion
#1

I am running into a strange problem that I am hoping someone can help me with.

I have a bunch of objects that have collision shapes associated with them that I have placed in a display group. I also have a player object that remains in the center of the screen that I am attempting to detect the collisions of the other, grouped objects.

Basically, I move the group around and attempt to detect the collisions.  In theory, I thought that this would work.  In practice, it does not.  It seems that the collisions are happening based on the x and y coordinates of the objects in relation to the group, not to the objects as they appear on screen.  For example, let’s assume the player character is at center x and center y.  Within the objects group are 2 objects, 1 at center x and center y+100 and number 2 at center x and center y + 200. 

I start the game with the whole group translated by -100 on the y axis.  Onscreen, the player is hitting the second object but in the physics engine, the player is hitting the first object.

Does anyone have any idea how I can fix this?

I hope that I have presented the problem in a way that makes sense.

Thanks,

Alan

#2

personally what i do is

obj.x = 0 obj.y = 0 -- THEN add the obj to the display group

physics should work fine after that. Also if you want to see exactly where your physics bodies are in relation to your objects, you can

physics.setDrawMode("hybrid")
#3

Interesting.  I’ll try adding the objects to the display group after setting up the physics.

What is also interesting is that I have been looking at this in the hybrid mode and the where the physics bodies appear (where I would expect them to, with their graphics) and where the physics engine detects them (where they would be without the containing group displacement) is what is completely throwing me off with this.

#4

personally what i do is

obj.x = 0 obj.y = 0 -- THEN add the obj to the display group

physics should work fine after that. Also if you want to see exactly where your physics bodies are in relation to your objects, you can

physics.setDrawMode("hybrid")
#5

Interesting.  I’ll try adding the objects to the display group after setting up the physics.

What is also interesting is that I have been looking at this in the hybrid mode and the where the physics bodies appear (where I would expect them to, with their graphics) and where the physics engine detects them (where they would be without the containing group displacement) is what is completely throwing me off with this.