An inverted Collision boxes (for 2.5D like stages)

[D0NM]

Hey everyone!
We make an open source game and we use Tiled as the stage editor.
It is used to set up sprites and collision polygons.
Now, I think that the approach when you have an unlimited walking area with obstacles is a complex thing to do in Tiled.
e.g. you should add more and more shapes to strict your units movements and keep the on the road.

Some pic of the Castle Crashers where they use polygons for both obstacles and walkable areas.



My idea is to leave only walkable areas polygons. All the rest space is an obstacle.
(Ofc, I want to keep some platforms and slanted places in the game, too)

I need your ideas and help on how to make it more easy with existing collisions libraries: HC, Bullet...

[pgimeno]

My idea is to leave only walkable areas polygons. All the rest space is an obstacle.

I can see why they have polygons for obstacles too. If you have, say, a column in the middle of a rectangular walkable area, in order to turn that column into an obstacle you have to subdivide the walkable area into at least four parts, in order to leave an unwalkable hole where the column is, while from a map designer perspective, it's easier to add a rectangular obstacle where the column is.

I need your ideas and help on how to make it more easy with existing collisions libraries: HC, Bullet...

Bullet? Do you mean Box2D?

I'd say Box2D doesn't adapt very well to 2.5D. You could perhaps create it as a top world view, without gravity, and make the slopes sensors, applying forces to the objects that pass through them depending on the angle.

[D0NM]

I can see why they have polygons for obstacles too. If you have, say, a column in the middle of a rectangular walkable area, in order to turn that column into an obstacle you have to subdivide the walkable area into at least four parts, in order to leave an unwalkable hole where the column is, while from a map designer perspective, it's easier to add a rectangular obstacle where the column is.

Thank you for a good point! You're right.

I need your ideas and help on how to make it more easy with existing collisions libraries: HC, Bullet...

Bullet? Do you mean Box2D?

Sorry, I mean Bump 2.0.

I'd say Box2D doesn't adapt very well to 2.5D. You could perhaps create it as a top world view, without gravity, and make the slopes sensors, applying forces to the objects that pass through them depending on the angle.

Some 2.5D games like "River City Ransom: Underground" use such physical engine.
Yes, I understand your idea.

Now I think to add another layer with obstacles that are passable but contain these vector forces and platform height.
I just cannot finish this idea's plan yet.