Mesh_Collision

3D collision detection, axis-aligned bounding boxes (AABB)

The main runs in the MeshCollision/main.cpp, we added the function checkCollision() that will find if exists, a collision between the shapes and will draw the smallest bounding boxes that collide.

In order to detect a collision we used a kd-tree, built from the vertices. Each node stores in addition to the vertices also the center, width, height and depth of the bounding box for the node, calculated from the sub-tree.

In addition to the drawing of the smallest bounding boxes in a collision, every shape holds it's mesh and a cube bounding mesh that is constructed from the root of the kdtree for that shape. Every frame we'll draw both meshes.

Project structure:

engine

This is the under-the-hood part that enables rendering meshes.

• mesh.cpp
  • Mesh represention via openGL.
• shader.cpp
  • Shader manager.
• obj_lodaer.cpp
  • .obj File parser.
  • Fast mesh simplification.
• Scene.cpp
  • Scene represention.
• CollisionDetection.h
  • Collision Detection algorithm calculations.
• KDTree.cpp
  • Adjusted kd-tree for collision detection.

MeshCollision

The actual MeshCollision implementation.

• main.cpp
  • Entry point.

Usage:

Keyboards controls:

Use arrows to control the movable shape around.

Use W,A,S,D to rotate the camera.

Q - Exit the program.

'Z' - Move the camera left.

'X' - Move the camera right.

'C' - Zoom into the scene.

'V' - Zoom out of the scene.

Future Possible Upgrades

• Use other structures for collision detection such as a BVH.
• Calculate the collsion enter,exit and stay.
• Have the calculation take less time.

Images: