id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	i_links	o_links
100	Terrain - Object Collision Detection	patrick	patrick	"Object - Terrain Collision Detection

Work in progress: The idea is to define pillars/wheels on which the object stands on. The object itself is abstracted as an OBB, I will use the 1st level obb of the object. There is no deeper (finer) CD with the Model itself, I don't think that it will be necessary nor utile.

To get the trianges, on which the wheel/pillar is standing, there needs to be some terrain separating algorithms. Height maps separate themselfs by default in regions, obj's will have to do this manualy.

To split the terrain manualy, it seems to be a good idea to split the terrain using barycentric coordinate representation. the idea is to parameterize space in terms of a set of points and their associated weights. A good resource on ""point in triangle"" thematics is applicable on blackpawn more o nthe barycentric coordinate representation and how to use the cross product on gamedev.

Now we know how to find out if one point is inside a triangle. But do we have to check all triangles in the terrain? The answer for this stupid question is of course ""no"". We partition the terrain into quadtrees gamedev forum and gamedev article this will be sufficient for CD performance and will also be easily enhanced to support frustum culling algorithms. LOD can be implemented later on as well (monstrous terrain article) 

see ticket nr 54"	defect	closed	major	0.3.5_playability orx-v0	CollisionDetection		fixed