问题1：如何在btHeightfieldTerrainShape中正确设置每个地形点的高度？

答案：您可以通过以下代码示例来设置每个地形点的高度，其中“heights”数组是地形网格的高度图：

float scaling = 2.0f / 65535.0f; // scaling factor to convert height map values to real height
int numVertsX = /* number of vertices along X axis */;
int numVertsY = /* number of vertices along Y axis */;
int minHeight = /* minimum height value in the height map */;

btVector3 localScaling(scaling, scaling, scaling);
btHeightfieldTerrainShape* terrainShape = new btHeightfieldTerrainShape(numVertsX, numVertsY, heights, 1.0f/*scale*/, minHeight, maxHeight, /*upAxis*/ 1, /*dataType*/ PHY_SHORT, /*flipQuadEdges*/ false);
terrainShape->setLocalScaling(localScaling);

问题2：如何在btHeightfieldTerrainShape中设置碰撞形状的旋转？

答案：您可以通过以下代码示例来设置碰撞形状的旋转：

btTransform transform;
transform.setIdentity();
transform.setOrigin(btVector3(0.0f, 0.0f, 0.0f)); // set position
transform.setRotation(btQuaternion(btVector3(0.0f, 0.0f, 1.0f), /*angle in radians*/ rotationAngle)); // set rotation
btDefaultMotionState* motionState = new btDefaultMotionState(transform);

float mass = 0.0f;
btVector3 localInertia(0.0f, 0.0f, 0.0f);
btRigidBody::btRigidBodyConstructionInfo rbInfo(mass, motionState, terrainShape, localInertia);
btRigidBody* terrainRigidBody = new btRigidBody(rbInfo);
terrainRigidBody->setActivationState(DISABLE_DEACTIVATION); // disable sleeping

在上面的代码中，“rotationAngle”是碰撞形状旋转的角度。请注意，您还需要在每个时间步骤中更新刚体的变换，以反映地形对象的运动。