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UPBGE: Fix compound ray cast with triangle child shape.
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Previously when a compound shape was hit by a ray cast the information about
the children triangles was inaccessible because of a lack from the bullet
API.

To fix this issue we have to keep the triangle index but add a child index
of the compound child shape hit. m_childIndex is dedicated for in LocalRayResult
and its value is set in rayTestSingleInternal, -1 for non compound shapes.

This value is catch from FilterClosestRayResultCallback and used in RayTest
to get the actual collision shape. To still get the shape construction info
of the children, each collision shape created has as user pointer the
shape costruction info. This object is get in RayTest to find the mesh
and polygon.

Tested with:
- mix of convex and concave shape in a compound shape.
- non compound concave and convex shape.
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@panzergame
panzergame committed Aug 19, 2018
1 parent 4a5055c commit fbbd184
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Showing 7 changed files with 119 additions and 127 deletions.
16 changes: 7 additions & 9 deletions extern/bullet/src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -340,8 +340,8 @@ void btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
collisionObjectWrap->getCollisionObject(),
0,
castResult.m_normal,
castResult.m_fraction
);
castResult.m_fraction,
-1);

bool normalInWorldSpace = true;
resultCallback.addSingleResult(localRayResult, normalInWorldSpace);
Expand Down Expand Up @@ -386,7 +386,8 @@ void btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
(m_collisionObject,
&shapeInfo,
hitNormalWorld,
hitFraction);
hitFraction,
-1);

bool normalInWorldSpace = true;
return m_resultCallback->addSingleResult(rayResult,normalInWorldSpace);
Expand Down Expand Up @@ -468,7 +469,8 @@ void btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
(m_collisionObject,
&shapeInfo,
hitNormalWorld,
hitFraction);
hitFraction,
-1);

bool normalInWorldSpace = true;
return m_resultCallback->addSingleResult(rayResult,normalInWorldSpace);
Expand Down Expand Up @@ -509,11 +511,7 @@ void btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con

virtual btScalar addSingleResult (btCollisionWorld::LocalRayResult &r, bool b)
{
btCollisionWorld::LocalShapeInfo shapeInfo;
shapeInfo.m_shapePart = -1;
shapeInfo.m_triangleIndex = m_i;
if (r.m_localShapeInfo == NULL)
r.m_localShapeInfo = &shapeInfo;
r.m_childIndex = m_i;

const btScalar result = m_userCallback->addSingleResult(r, b);
m_closestHitFraction = m_userCallback->m_closestHitFraction;
Expand Down
8 changes: 5 additions & 3 deletions extern/bullet/src/BulletCollision/CollisionDispatch/btCollisionWorld.h
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Original file line number Diff line number Diff line change
Expand Up @@ -188,19 +188,21 @@ class btCollisionWorld
LocalRayResult(const btCollisionObject* collisionObject,
LocalShapeInfo* localShapeInfo,
const btVector3& hitNormalLocal,
btScalar hitFraction)
btScalar hitFraction,
int childIndex)
:m_collisionObject(collisionObject),
m_localShapeInfo(localShapeInfo),
m_hitNormalLocal(hitNormalLocal),
m_hitFraction(hitFraction)
m_hitFraction(hitFraction),
m_childIndex(childIndex)
{
}

const btCollisionObject* m_collisionObject;
LocalShapeInfo* m_localShapeInfo;
btVector3 m_hitNormalLocal;
btScalar m_hitFraction;

int m_childIndex;
};

///RayResultCallback is used to report new raycast results
Expand Down
3 changes: 2 additions & 1 deletion extern/bullet/src/BulletSoftBody/btSoftMultiBodyDynamicsWorld.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -317,7 +317,8 @@ void btSoftMultiBodyDynamicsWorld::rayTestSingle(const btTransform& rayFromTrans
(collisionObject,
&shapeInfo,
normal,
softResult.fraction);
softResult.fraction,
-1);
bool normalInWorldSpace = true;
resultCallback.addSingleResult(rayResult,normalInWorldSpace);
}
Expand Down
3 changes: 2 additions & 1 deletion extern/bullet/src/BulletSoftBody/btSoftRigidDynamicsWorld.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -317,7 +317,8 @@ void btSoftRigidDynamicsWorld::rayTestSingle(const btTransform& rayFromTrans,con
(collisionObject,
&shapeInfo,
normal,
softResult.fraction);
softResult.fraction,
-1);
bool normalInWorldSpace = true;
resultCallback.addSingleResult(rayResult,normalInWorldSpace);
}
Expand Down
3 changes: 2 additions & 1 deletion extern/bullet/src/BulletSoftBody/btSoftRigidDynamicsWorldMt.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -318,7 +318,8 @@ void btSoftRigidDynamicsWorldMt::rayTestSingle(const btTransform& rayFromTrans,c
(collisionObject,
&shapeInfo,
normal,
softResult.fraction);
softResult.fraction,
-1);
bool normalInWorldSpace = true;
resultCallback.addSingleResult(rayResult,normalInWorldSpace);
}
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5 changes: 5 additions & 0 deletions source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2142,6 +2142,11 @@ btCollisionShape *CcdShapeConstructionInfo::CreateBulletShape(btScalar margin, b
BLI_assert(false);
}
}

if (collisionShape) {
collisionShape->setUserPointer(this);
}

return collisionShape;
}

Expand Down
208 changes: 96 additions & 112 deletions source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1101,13 +1101,13 @@ void CcdPhysicsEnvironment::RemoveConstraintById(int constraintId, bool free)

struct FilterClosestRayResultCallback : public btCollisionWorld::ClosestRayResultCallback {
PHY_IRayCastFilterCallback& m_phyRayFilter;
const btCollisionShape *m_hitTriangleShape;
int m_hitChildIndex;
int m_hitTriangleIndex;

FilterClosestRayResultCallback(PHY_IRayCastFilterCallback& phyRayFilter, const btVector3& rayFrom, const btVector3& rayTo)
:btCollisionWorld::ClosestRayResultCallback(rayFrom, rayTo),
m_phyRayFilter(phyRayFilter),
m_hitTriangleShape(nullptr),
m_hitChildIndex(-1),
m_hitTriangleIndex(0)
{
}
Expand All @@ -1134,21 +1134,18 @@ struct FilterClosestRayResultCallback : public btCollisionWorld::ClosestRayResu

virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult, bool normalInWorldSpace)
{
//CcdPhysicsController* curHit = static_cast<CcdPhysicsController*>(rayResult.m_collisionObject->getUserPointer());
// save shape information as ClosestRayResultCallback::AddSingleResult() does not do it
m_hitChildIndex = rayResult.m_childIndex;
if (rayResult.m_localShapeInfo) {
m_hitTriangleShape = rayResult.m_collisionObject->getCollisionShape();
m_hitTriangleIndex = rayResult.m_localShapeInfo->m_triangleIndex;
}
else {
m_hitTriangleShape = nullptr;
m_hitTriangleIndex = 0;
}
return ClosestRayResultCallback::addSingleResult(rayResult, normalInWorldSpace);
}
};

static bool GetHitTriangle(btCollisionShape *shape, CcdShapeConstructionInfo *shapeInfo, int hitTriangleIndex, btVector3 triangle[])
static bool GetHitTriangle(const btCollisionShape *shape, CcdShapeConstructionInfo *shapeInfo, int hitTriangleIndex, btVector3 triangle[])
{
// this code is copied from Bullet
const unsigned char *vertexbase;
Expand Down Expand Up @@ -1198,132 +1195,119 @@ PHY_IPhysicsController *CcdPhysicsEnvironment::RayTest(PHY_IRayCastFilterCallbac

//Either Ray Cast with or without filtering

//btCollisionWorld::ClosestRayResultCallback rayCallback(rayFrom,rayTo);
FilterClosestRayResultCallback rayCallback(filterCallback, rayFrom, rayTo);

PHY_RayCastResult result;

// don't collision with sensor object
rayCallback.m_collisionFilterMask = CcdConstructionInfo::AllFilter ^ CcdConstructionInfo::SensorFilter;
// use faster (less accurate) ray callback, works better with 0 collision margins
rayCallback.m_flags |= btTriangleRaycastCallback::kF_UseSubSimplexConvexCastRaytest;
//, ,filterCallback.m_faceNormal);

m_dynamicsWorld->rayTest(rayFrom, rayTo, rayCallback);
if (rayCallback.hasHit()) {
const btCollisionObject *object = rayCallback.m_collisionObject;
const btCollisionShape *shape = object->getCollisionShape();

CcdPhysicsController *controller = static_cast<CcdPhysicsController *>(rayCallback.m_collisionObject->getUserPointer());
result.m_controller = controller;
result.m_hitPoint[0] = rayCallback.m_hitPointWorld.getX();
result.m_hitPoint[1] = rayCallback.m_hitPointWorld.getY();
result.m_hitPoint[2] = rayCallback.m_hitPointWorld.getZ();

if (rayCallback.m_hitTriangleShape != nullptr) {
// identify the mesh polygon
CcdShapeConstructionInfo *shapeInfo = controller->m_shapeInfo;
if (shapeInfo) {
btCollisionShape *shape = controller->GetCollisionObject()->getCollisionShape();
if (shape->isCompound()) {
btCompoundShape *compoundShape = (btCompoundShape *)shape;
CcdShapeConstructionInfo *compoundShapeInfo = shapeInfo;
// need to search which sub-shape has been hit
for (int i = 0; i < compoundShape->getNumChildShapes(); i++) {
shapeInfo = compoundShapeInfo->GetChildShape(i);
shape = compoundShape->getChildShape(i);
if (shape == rayCallback.m_hitTriangleShape) {
break;
result.m_hitPoint = ToMt(rayCallback.m_hitPointWorld);

if (shape) {
if (shape->isCompound()) {
const btCompoundShape *compoundShape = static_cast<const btCompoundShape *>(shape);
shape = compoundShape->getChildShape(rayCallback.m_hitChildIndex);
}

CcdShapeConstructionInfo *shapeInfo = static_cast<CcdShapeConstructionInfo *>(shape->getUserPointer());
if (shapeInfo && rayCallback.m_hitTriangleIndex < shapeInfo->m_polygonIndexArray.size()) {
// save original collision shape triangle for soft body
const int hitTriangleIndex = rayCallback.m_hitTriangleIndex;

result.m_meshObject = shapeInfo->GetMesh();
if (shape->isSoftBody()) {
// soft body using different face numbering because of randomization
// hopefully we have stored the original face number in m_tag
const btSoftBody *softBody = static_cast<const btSoftBody *>(object);
if (softBody->m_faces[hitTriangleIndex].m_tag != 0) {
rayCallback.m_hitTriangleIndex = (int)((uintptr_t)(softBody->m_faces[hitTriangleIndex].m_tag) - 1);
}
}
// retrieve the original mesh polygon (in case of quad->tri conversion)
result.m_polygon = shapeInfo->m_polygonIndexArray[rayCallback.m_hitTriangleIndex];
// hit triangle in world coordinate, for face normal and UV coordinate
btVector3 triangle[3];
bool triangleOK = false;
if (filterCallback.m_faceUV && (3 * rayCallback.m_hitTriangleIndex) < shapeInfo->m_triFaceUVcoArray.size()) {
// interpolate the UV coordinate of the hit point
CcdShapeConstructionInfo::UVco *uvCo = &shapeInfo->m_triFaceUVcoArray[3 * rayCallback.m_hitTriangleIndex];
// 1. get the 3 coordinate of the triangle in world space
btVector3 v1, v2, v3;
if (shape->isSoftBody()) {
// soft body give points directly in world coordinate
const btSoftBody *softBody = static_cast<const btSoftBody *>(object);
v1 = softBody->m_faces[hitTriangleIndex].m_n[0]->m_x;
v2 = softBody->m_faces[hitTriangleIndex].m_n[1]->m_x;
v3 = softBody->m_faces[hitTriangleIndex].m_n[2]->m_x;
}
else {
// for rigid body we must apply the world transform
triangleOK = GetHitTriangle(shape, shapeInfo, hitTriangleIndex, triangle);
if (!triangleOK) {
// if we cannot get the triangle, no use to continue
goto SKIP_UV_NORMAL;
}
const btTransform& trans = object->getWorldTransform();
v1 = trans(triangle[0]);
v2 = trans(triangle[1]);
v3 = trans(triangle[2]);
}
// 2. compute barycentric coordinate of the hit point
btVector3 v = v2 - v1;
btVector3 w = v3 - v1;
btVector3 u = v.cross(w);
btScalar A = u.length();

v = v2 - rayCallback.m_hitPointWorld;
w = v3 - rayCallback.m_hitPointWorld;
u = v.cross(w);
btScalar A1 = u.length();

v = rayCallback.m_hitPointWorld - v1;
w = v3 - v1;
u = v.cross(w);
btScalar A2 = u.length();

btVector3 baryCo;
baryCo.setX(A1 / A);
baryCo.setY(A2 / A);
baryCo.setZ(1.0f - baryCo.getX() - baryCo.getY());
// 3. compute UV coordinate
result.m_hitUV[0] = baryCo.getX() * uvCo[0].uv[0] + baryCo.getY() * uvCo[1].uv[0] + baryCo.getZ() * uvCo[2].uv[0];
result.m_hitUV[1] = baryCo.getX() * uvCo[0].uv[1] + baryCo.getY() * uvCo[1].uv[1] + baryCo.getZ() * uvCo[2].uv[1];
result.m_hitUVOK = 1;
}
if (shape == rayCallback.m_hitTriangleShape &&
rayCallback.m_hitTriangleIndex < shapeInfo->m_polygonIndexArray.size()) {
// save original collision shape triangle for soft body
int hitTriangleIndex = rayCallback.m_hitTriangleIndex;

result.m_meshObject = shapeInfo->GetMesh();
// Bullet returns the normal from "outside".
// If the user requests the real normal, compute it now
if (filterCallback.m_faceNormal) {
if (shape->isSoftBody()) {
// soft body using different face numbering because of randomization
// hopefully we have stored the original face number in m_tag
// we can get the real normal directly from the body
const btSoftBody *softBody = static_cast<const btSoftBody *>(rayCallback.m_collisionObject);
if (softBody->m_faces[hitTriangleIndex].m_tag != 0) {
rayCallback.m_hitTriangleIndex = (int)((uintptr_t)(softBody->m_faces[hitTriangleIndex].m_tag) - 1);
}
rayCallback.m_hitNormalWorld = softBody->m_faces[hitTriangleIndex].m_normal;
}
// retrieve the original mesh polygon (in case of quad->tri conversion)
result.m_polygon = shapeInfo->m_polygonIndexArray[rayCallback.m_hitTriangleIndex];
// hit triangle in world coordinate, for face normal and UV coordinate
btVector3 triangle[3];
bool triangleOK = false;
if (filterCallback.m_faceUV && (3 * rayCallback.m_hitTriangleIndex) < shapeInfo->m_triFaceUVcoArray.size()) {
// interpolate the UV coordinate of the hit point
CcdShapeConstructionInfo::UVco *uvCo = &shapeInfo->m_triFaceUVcoArray[3 * rayCallback.m_hitTriangleIndex];
// 1. get the 3 coordinate of the triangle in world space
btVector3 v1, v2, v3;
if (shape->isSoftBody()) {
// soft body give points directly in world coordinate
const btSoftBody *softBody = static_cast<const btSoftBody *>(rayCallback.m_collisionObject);
v1 = softBody->m_faces[hitTriangleIndex].m_n[0]->m_x;
v2 = softBody->m_faces[hitTriangleIndex].m_n[1]->m_x;
v3 = softBody->m_faces[hitTriangleIndex].m_n[2]->m_x;
}
else {
// for rigid body we must apply the world transform
else {
if (!triangleOK) {
triangleOK = GetHitTriangle(shape, shapeInfo, hitTriangleIndex, triangle);
if (!triangleOK) {
// if we cannot get the triangle, no use to continue
goto SKIP_UV_NORMAL;
}
v1 = rayCallback.m_collisionObject->getWorldTransform()(triangle[0]);
v2 = rayCallback.m_collisionObject->getWorldTransform()(triangle[1]);
v3 = rayCallback.m_collisionObject->getWorldTransform()(triangle[2]);
}
// 2. compute barycentric coordinate of the hit point
btVector3 v = v2 - v1;
btVector3 w = v3 - v1;
btVector3 u = v.cross(w);
btScalar A = u.length();

v = v2 - rayCallback.m_hitPointWorld;
w = v3 - rayCallback.m_hitPointWorld;
u = v.cross(w);
btScalar A1 = u.length();

v = rayCallback.m_hitPointWorld - v1;
w = v3 - v1;
u = v.cross(w);
btScalar A2 = u.length();

btVector3 baryCo;
baryCo.setX(A1 / A);
baryCo.setY(A2 / A);
baryCo.setZ(1.0f - baryCo.getX() - baryCo.getY());
// 3. compute UV coordinate
result.m_hitUV[0] = baryCo.getX() * uvCo[0].uv[0] + baryCo.getY() * uvCo[1].uv[0] + baryCo.getZ() * uvCo[2].uv[0];
result.m_hitUV[1] = baryCo.getX() * uvCo[0].uv[1] + baryCo.getY() * uvCo[1].uv[1] + baryCo.getZ() * uvCo[2].uv[1];
result.m_hitUVOK = 1;
}

// Bullet returns the normal from "outside".
// If the user requests the real normal, compute it now
if (filterCallback.m_faceNormal) {
if (shape->isSoftBody()) {
// we can get the real normal directly from the body
const btSoftBody *softBody = static_cast<const btSoftBody *>(rayCallback.m_collisionObject);
rayCallback.m_hitNormalWorld = softBody->m_faces[hitTriangleIndex].m_normal;
}
else {
if (!triangleOK) {
triangleOK = GetHitTriangle(shape, shapeInfo, hitTriangleIndex, triangle);
}
if (triangleOK) {
btVector3 triangleNormal;
triangleNormal = (triangle[1] - triangle[0]).cross(triangle[2] - triangle[0]);
rayCallback.m_hitNormalWorld = rayCallback.m_collisionObject->getWorldTransform().getBasis() * triangleNormal;
}
if (triangleOK) {
btVector3 triangleNormal;
triangleNormal = (triangle[1] - triangle[0]).cross(triangle[2] - triangle[0]);
rayCallback.m_hitNormalWorld = rayCallback.m_collisionObject->getWorldTransform().getBasis() * triangleNormal;
}
}
SKIP_UV_NORMAL:
;
}
SKIP_UV_NORMAL:
;
}
}
if (rayCallback.m_hitNormalWorld.length2() > (SIMD_EPSILON * SIMD_EPSILON)) {
Expand All @@ -1332,9 +1316,8 @@ PHY_IPhysicsController *CcdPhysicsEnvironment::RayTest(PHY_IRayCastFilterCallbac
else {
rayCallback.m_hitNormalWorld.setValue(1.0f, 0.0f, 0.0f);
}
result.m_hitNormal[0] = rayCallback.m_hitNormalWorld.getX();
result.m_hitNormal[1] = rayCallback.m_hitNormalWorld.getY();
result.m_hitNormal[2] = rayCallback.m_hitNormalWorld.getZ();

result.m_hitNormal = ToMt(rayCallback.m_hitNormalWorld);
filterCallback.reportHit(&result);
}

Expand Down Expand Up @@ -3004,6 +2987,7 @@ void CcdPhysicsEnvironment::ConvertObject(BL_SceneConverter& converter, KX_GameO
// create the compound shape manually as we already have the child shape
btCompoundShape *compoundShape = new btCompoundShape();
compoundShape->addChildShape(shapeInfo->m_childTrans, bm);
compoundShape->setUserPointer(compoundShapeInfo);
// now replace the shape
bm = compoundShape;
shapeInfo->Release();
Expand Down

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