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basic support for height fields. They are producing temporary triangles, similar to the plane shape.

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This commit is contained in:
ejcoumans
2007-06-27 03:19:34 +00:00
parent bba61c834c
commit 3ca6d7385e
2 changed files with 262 additions and 32 deletions
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271
src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.cpp
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@@ -18,9 +18,65 @@ subject to the following restrictions:
#include "LinearMath/btTransformUtil.h"
btHeightfieldTerrainShape::btHeightfieldTerrainShape()
:m_localScaling(btScalar(0.),btScalar(0.),btScalar(0.))
btHeightfieldTerrainShape::btHeightfieldTerrainShape(int width,int length,unsigned char* heightfieldData,btScalar maxHeight,int upAxis)
:m_localScaling(btScalar(1.),btScalar(1.),btScalar(1.)),
m_width(width),
m_length(length),
m_heightfieldData(heightfieldData),
m_maxHeight(maxHeight),
m_upAxis(upAxis)
{
btScalar quantizationMargin = 1.f;
//enlarge the AABB to avoid division by zero when initializing the quantization values
btVector3 clampValue(quantizationMargin,quantizationMargin,quantizationMargin);
btVector3 halfExtents(0,0,0);
switch (m_upAxis)
{
case 0:
{
halfExtents.setValue(
m_maxHeight,
m_width,
m_length);
break;
}
case 1:
{
halfExtents.setValue(
m_width,
m_maxHeight,
m_length);
break;
};
case 2:
{
halfExtents.setValue(
m_width,
m_length,
m_maxHeight
);
break;
}
default:
{
//need to get valid m_upAxis
btAssert(0);
}
}
halfExtents*= btScalar(0.5);
m_localAabbMin = -halfExtents - clampValue;
m_localAabbMax = halfExtents + clampValue;
btVector3 aabbSize = m_localAabbMax - m_localAabbMin;
m_quantization = btVector3(btScalar(65535.0),btScalar(65535.0),btScalar(65535.0)) / aabbSize;
}
@@ -30,51 +86,206 @@ btHeightfieldTerrainShape::~btHeightfieldTerrainShape()
void btHeightfieldTerrainShape::getAabb(const btTransform& ,btVector3& aabbMin,btVector3& aabbMax) const
void btHeightfieldTerrainShape::getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
{
aabbMin.setValue(btScalar(-1e30),btScalar(-1e30),btScalar(-1e30));
aabbMax.setValue(btScalar(1e30),btScalar(1e30),btScalar(1e30));
/*
aabbMin.setValue(-1e30f,-1e30f,-1e30f);
aabbMax.setValue(1e30f,1e30f,1e30f);
*/
btVector3 halfExtents = (m_localAabbMax-m_localAabbMin)* m_localScaling * btScalar(0.5);
btMatrix3x3 abs_b = t.getBasis().absolute();
btPoint3 center = t.getOrigin();
btVector3 extent = btVector3(abs_b[0].dot(halfExtents),
abs_b[1].dot(halfExtents),
abs_b[2].dot(halfExtents));
extent += btVector3(getMargin(),getMargin(),getMargin());
aabbMin = center - extent;
aabbMax = center + extent;
}
void btHeightfieldTerrainShape::getVertex(int x,int y,btVector3& vertex) const
{
btAssert(x>=0);
btAssert(y>=0);
btAssert(x<m_width);
btAssert(y<m_length);
unsigned char heightFieldValue = m_heightfieldData[(y*m_width)+x];
switch (m_upAxis)
{
case 0:
{
vertex.setValue(
heightFieldValue* (m_maxHeight/btScalar(65535)),
(-m_width/2 ) + x,
(-m_length/2 ) + y
);
break;
}
case 1:
{
vertex.setValue(
(-m_width/2 ) + x,
heightFieldValue* (m_maxHeight/btScalar(65535)),
(-m_length/2 ) + y
);
break;
};
case 2:
{
vertex.setValue(
(-m_width/2 ) + x,
(-m_length/2 ) + y,
heightFieldValue* (m_maxHeight/btScalar(65535))
);
break;
}
default:
{
//need to get valid m_upAxis
btAssert(0);
}
}
vertex*=m_localScaling;
}
void btHeightfieldTerrainShape::quantizeWithClamp(short* out, const btVector3& point) const
{
btVector3 clampedPoint(point);
clampedPoint.setMax(m_localAabbMin);
clampedPoint.setMin(m_localAabbMax);
btVector3 v = (clampedPoint );// * m_quantization;
out[0] = (short)(v.getX());
out[1] = (short)(v.getY());
out[2] = (short)(v.getZ());
//correct for
}
void btHeightfieldTerrainShape::processAllTriangles(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) const
{
(void)callback;
(void)aabbMax;
(void)aabbMin;
/*
btVector3 halfExtents = (aabbMax - aabbMin) * btScalar(0.5);
btVector3 center = (aabbMax + aabbMin) * btScalar(0.5);
//quantize the aabbMin and aabbMax, and adjust the start/end ranges
short quantizedAabbMin[3];
short quantizedAabbMax[3];
btVector3 localAabbMin = aabbMin*btVector3(1.f/m_localScaling[0],1.f/m_localScaling[1],1.f/m_localScaling[2]);
btVector3 localAabbMax = aabbMax*btVector3(1.f/m_localScaling[0],1.f/m_localScaling[1],1.f/m_localScaling[2]);
quantizeWithClamp(quantizedAabbMin, localAabbMin);
quantizeWithClamp(quantizedAabbMax, localAabbMax);
//TODO
//this is where the triangles are generated, given AABB and plane equation (normal/constant)
btVector3 tangentDir0,tangentDir1;
//tangentDir0/tangentDir1 can be precalculated
btPlaneSpace1(m_planeNormal,tangentDir0,tangentDir1);
btVector3 supVertex0,supVertex1;
btVector3 projectedCenter = center - (m_planeNormal.dot(center) - m_planeConstant)*m_planeNormal;
btVector3 triangle[3];
btScalar radius = halfExtents.length();
triangle[0] = projectedCenter + tangentDir0*radius + tangentDir1*radius;
triangle[1] = projectedCenter + tangentDir0*radius - tangentDir1*radius;
triangle[2] = projectedCenter - tangentDir0*radius - tangentDir1*radius;
callback->processTriangle(triangle,0,0);
int startX=0;
int endX=m_width-1;
int startJ=0;
int endJ=m_length-1;
triangle[0] = projectedCenter - tangentDir0*radius - tangentDir1*radius;
triangle[1] = projectedCenter - tangentDir0*radius + tangentDir1*radius;
triangle[2] = projectedCenter + tangentDir0*radius + tangentDir1*radius;
switch (m_upAxis)
{
case 0:
{
quantizedAabbMin[1]+=m_width/2-1;
quantizedAabbMax[1]+=m_width/2+1;
quantizedAabbMin[2]+=m_length/2-1;
quantizedAabbMax[2]+=m_length/2+1;
callback->processTriangle(triangle,0,1);
*/
if (quantizedAabbMin[1]>startX)
startX = quantizedAabbMin[1];
if (quantizedAabbMax[1]<endX)
endX = quantizedAabbMax[1];
if (quantizedAabbMin[2]>startJ)
startJ = quantizedAabbMin[2];
if (quantizedAabbMax[2]<endJ)
endJ = quantizedAabbMax[2];
break;
}
case 1:
{
quantizedAabbMin[0]+=m_width/2-1;
quantizedAabbMax[0]+=m_width/2+1;
quantizedAabbMin[2]+=m_length/2-1;
quantizedAabbMax[2]+=m_length/2+1;
if (quantizedAabbMin[0]>startX)
startX = quantizedAabbMin[0];
if (quantizedAabbMax[0]<endX)
endX = quantizedAabbMax[0];
if (quantizedAabbMin[2]>startJ)
startJ = quantizedAabbMin[2];
if (quantizedAabbMax[2]<endJ)
endJ = quantizedAabbMax[2];
break;
};
case 2:
{
quantizedAabbMin[0]+=m_width/2-1;
quantizedAabbMax[0]+=m_width/2+1;
quantizedAabbMin[1]+=m_length/2-1;
quantizedAabbMax[1]+=m_length/2+1;
if (quantizedAabbMin[0]>startX)
startX = quantizedAabbMin[0];
if (quantizedAabbMax[0]<endX)
endX = quantizedAabbMax[0];
if (quantizedAabbMin[1]>startJ)
startJ = quantizedAabbMin[1];
if (quantizedAabbMax[1]<endJ)
endJ = quantizedAabbMax[1];
break;
}
default:
{
//need to get valid m_upAxis
btAssert(0);
}
}
for(int j=startJ; j<endJ; j++)
{
for(int x=startX; x<endX; x++)
{
btVector3 vertices[3];
//first triangle
getVertex(x,j,vertices[0]);
getVertex(x,j+1,vertices[1]);
getVertex(x+1,j,vertices[2]);
callback->processTriangle(vertices,x,j);
//second triangle
getVertex(x+1,j,vertices[0]);
getVertex(x,j+1,vertices[1]);
getVertex(x+1,j+1,vertices[2]);
callback->processTriangle(vertices,x,j);
}
}
}

23
src/BulletCollision/CollisionShapes/btHeightfieldTerrainShape.h
View File

@@ -25,12 +25,31 @@ protected:
btVector3 m_localAabbMin;
btVector3 m_localAabbMax;
//todo: terrain data
///terrain data
int m_width;
int m_length;
btScalar m_maxHeight;
unsigned char* m_heightfieldData;
int m_upAxis;
btVector3 m_quantization;
btVector3 m_localScaling;
void quantizeWithClamp(short* out, const btVector3& point) const;
void getVertex(int x,int y,btVector3& vertex) const;
inline bool testQuantizedAabbAgainstQuantizedAabb(short int* aabbMin1,short int* aabbMax1,const short int* aabbMin2,const short int* aabbMax2) const
{
bool overlap = true;
overlap = (aabbMin1[0] > aabbMax2[0] || aabbMax1[0] < aabbMin2[0]) ? false : overlap;
overlap = (aabbMin1[2] > aabbMax2[2] || aabbMax1[2] < aabbMin2[2]) ? false : overlap;
overlap = (aabbMin1[1] > aabbMax2[1] || aabbMax1[1] < aabbMin2[1]) ? false : overlap;
return overlap;
}
public:
btHeightfieldTerrainShape();
btHeightfieldTerrainShape(int width,int height,unsigned char* heightfieldData, btScalar maxHeight,int upAxis);
virtual ~btHeightfieldTerrainShape();