Project

https://graphics.cs.utah.edu/research/projects/shortest-path-to-boundary/

Build and Debug

Fork:(在Win10上）
https://github.com/chunleili/Shortest-Path-to-Boundary-for-Self-Intersecting-Meshes

commit hash
d3160168d2b6a58188d12e6cd959da0ac9b56e95

./vscode/launch.json
{
“version”: “0.2.0”,
“configurations”: [
{
“name”: “(msvc) Launch”,
“type”: “cppvsdbg”,
“request”: “launch”,
// Resolved by CMake Tools:
“program”: “$workspaceFolder/build/Debug/Shortest-Path-Test.exe","args":["TestData/Parameters.json","TestData/IntersectingShape.t"],"stopAtEntry":true,"cwd":"${workspaceFolder}”,
“environment”: [
{
// add the directory where our target was built to the PATHs
// it gets resolved by CMake Tools:
“name”: “PATH”,
“value”: “$env:PATH:${command:cmake.getLaunchTargetDirectory}”
},
],
“console”: “internalConsole”,
}
]
}

Code Explain

Test.cpp中是入口main函数
40行之前是初始化（mesh和param)
在这个for loop当中查找每个Vert的最近点。

关键的函数
dcd.vertexCollisionDetection(iV, meshId, &colDecResult);
用BVH做碰撞检测。（Broad Phase)

dcd.closestPointQuery(&colDecResult, &queryResult);
用碰撞检测后的结果查找最近点。(Narrow Phase)

Broad Phase：vertexCollisionDetection

核心就rtcPointQuery，调用的是intel embree的API

D:\Dev\Shortest-Path-to-Boundary-for-Self-Intersecting-Meshes\ShortestPath\CollisionDetector\DiscreteCollisionDetector.cpp
L598

https://github.com/chunleili/Shortest-Path-to-Boundary-for-Self-Intersecting-Meshes/blob/5be890b7775dc92cde410895d124c81162bee978/ShortestPath/CollisionDetector/DiscreteCollisionDetector.cpp#L598

Narrow Phase: closestPointQuery

https://github.com/chunleili/Shortest-Path-to-Boundary-for-Self-Intersecting-Meshes/blob/5be890b7775dc92cde410895d124c81162bee978/ShortestPath/CollisionDetector/DiscreteCollisionDetector.cpp#L621

其中较为关键的是idTetIntersected，表示相交的四面体的id。intersectedTets则是所有相交四面的的array。

执行查询最近点：
rtcPointQuery(surfaceMeshScenes[idTMIntersected], &query, &context, nullptr, (void*)pClosestPtResult); 仍然是用API来查询点。目的是针对某个表面网格（surfaceMeshScenes[idTMIntersected]），找到距离查询点最近的表面点，并把结果存储在 pClosestPtResult 中。

接下来是存储找到的最近点的信息：其face id, 坐标， barycentric coord.

另外，rtc是根据注册机制自动调用一些hook函数的例如比较关键的是

其中checkTetTraverse这个flag表示检查四面体的遍历，正是文中提到的连接性检测（valid path)