MeshGenerator.h

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// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.  
 
#ifndef PHYSX_MESHGENERATOR_H
#define PHYSX_MESHGENERATOR_H
 
#include "PxPhysicsAPI.h"
#include "extensions/PxRemeshingExt.h"
 
namespace meshgenerator
{
using namespace physx;
 
void createCube(PxArray<PxVec3>& triVerts, PxArray<PxU32>& triIndices, const PxVec3& pos, PxReal scaling)
{
    triVerts.clear();
    triIndices.clear();
    triVerts.pushBack(scaling * PxVec3(0.5f, -0.5f, -0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(0.5f, -0.5f, 0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(-0.5f, -0.5f, 0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(-0.5f, -0.5f, -0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(0.5f, 0.5f, -0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(0.5f, 0.5f, 0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(-0.5f, 0.5f, 0.5f) + pos);
    triVerts.pushBack(scaling * PxVec3(-0.5f, 0.5f, -0.5f) + pos);
 
    triIndices.pushBack(1); triIndices.pushBack(2); triIndices.pushBack(3);
    triIndices.pushBack(7); triIndices.pushBack(6); triIndices.pushBack(5);
    triIndices.pushBack(4); triIndices.pushBack(5); triIndices.pushBack(1);
    triIndices.pushBack(5); triIndices.pushBack(6); triIndices.pushBack(2);
 
    triIndices.pushBack(2); triIndices.pushBack(6); triIndices.pushBack(7);
    triIndices.pushBack(0); triIndices.pushBack(3); triIndices.pushBack(7);
    triIndices.pushBack(0); triIndices.pushBack(1); triIndices.pushBack(3);
    triIndices.pushBack(4); triIndices.pushBack(7); triIndices.pushBack(5);
 
    triIndices.pushBack(0); triIndices.pushBack(4); triIndices.pushBack(1);
    triIndices.pushBack(1); triIndices.pushBack(5); triIndices.pushBack(2);
    triIndices.pushBack(3); triIndices.pushBack(2); triIndices.pushBack(7);
    triIndices.pushBack(4); triIndices.pushBack(0); triIndices.pushBack(7);
}
 
void createConeY(PxArray<PxVec3>& triVerts, PxArray<PxU32>& triIndices, const PxVec3& center, PxReal radius, PxReal height, PxU32 numPointsOnRing = 32)
{
    triVerts.clear();
    triIndices.clear();
    for (PxU32 i = 0; i < numPointsOnRing; ++i)
    {
        PxReal angle = i * 2.0f * 3.1415926535898f / numPointsOnRing;
        triVerts.pushBack(center + radius * PxVec3(PxSin(angle), 0, PxCos(angle)));
    }
 
    triVerts.pushBack(center);
    triVerts.pushBack(center + PxVec3(0, height, 0));
    for (PxU32 i = 0; i < numPointsOnRing; ++i)
    {
        triIndices.pushBack(numPointsOnRing);  triIndices.pushBack(i); triIndices.pushBack((i + 1) % numPointsOnRing);
        triIndices.pushBack(numPointsOnRing + 1); triIndices.pushBack((i + 1) % numPointsOnRing); triIndices.pushBack(i);
    }
}
 
void projectPointsOntoSphere(PxArray<PxVec3>& triVerts, const PxVec3& center, PxReal radius)
{
    for (PxU32 i = 0; i < triVerts.size(); ++i)
    {
        PxVec3 dir = triVerts[i] - center;
        dir.normalize();
        triVerts[i] = center + radius * dir;
    }
}
 
void projectPointsOntoBowl(PxArray<PxVec3>& triVerts, const PxVec3& center, PxReal radius)
{
    for (PxU32 i = 0; i < triVerts.size(); ++i)
    {
        PxVec3 dir = triVerts[i] - center;
        dir.normalize();
 
        if (dir.y > 0.01f) 
        {
            dir.x *= 0.9f;
            dir.z *= 0.9f;
            dir.y = -dir.y;
        }
 
        triVerts[i] = center + radius * dir;
    }
}
 
void createBowl(PxArray<PxVec3>& triVerts, PxArray<PxU32>& triIndices, const PxVec3& center, PxReal radius, const PxReal maxEdgeLength)
{
    triVerts.clear();
    triIndices.clear();
    createCube(triVerts, triIndices, center, radius);
    projectPointsOntoSphere(triVerts, center, radius);
 
    while (PxRemeshingExt::limitMaxEdgeLength(triIndices, triVerts, maxEdgeLength, 1))  
        projectPointsOntoSphere(triVerts, center, radius);      
    
    projectPointsOntoBowl(triVerts, center, radius);
}
}
 
#endif