mesh rigidbody drawing

2024-03-23 16:38

文章标签 mesh drawing rigidbody

本文主要是介绍mesh rigidbody drawing，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

方法一：获取顶点和索引的方法来画出碰撞膜

hkpRigidBody* createMesh(const hkVector4& position, hkReal scale)
{
    hkpStorageExtendedMeshShape* extendedMesh = new hkpStorageExtendedMeshShape();
    for(int numobj=0; numobj<m.Objects[numobj].numObjects; numobj++)
    {
        hkpSimpleMeshShape* meshShape = new hkpSimpleMeshShape( 0.05f );
        {
            int side=m.Objects[numobj].numVerts;
            meshShape->m_vertices.setSize( side );
            for (int j = 0; j < side; j++ )
            {
                hkVector4 vertex (m.Objects[numobj].Vertexes[j*3+0],
                m.Objects[numobj].Vertexes[j*3+1],
                m.Objects[numobj].Vertexes[j*3+2] );
                //vertex.add4(position);
                vertex.mul4(scale);
                meshShape->m_vertices[j] = vertex ;
            }

            side=m.Objects[numobj].numFaces/3;
            meshShape->m_triangles.setSize( side);
            for (int j = 0; j < side; j++ )
            {
                meshShape->m_triangles[j].m_a = m.Objects[numobj].Faces[3*j+0];
                meshShape->m_triangles[j].m_b = m.Objects[numobj].Faces[3*j+1];
                meshShape->m_triangles[j].m_c = m.Objects[numobj].Faces[3*j+2];
            }
        }

        hkpExtendedMeshShape::TrianglesSubpart part;
        part.m_numTriangleShapes = meshShape->m_triangles.getSize();
        part.m_numVertices = meshShape->m_vertices.getSize();
        part.m_vertexBase = (float*)meshShape->m_vertices.begin();
        part.m_stridingType = hkpExtendedMeshShape::INDICES_INT16;
        part.m_vertexStriding = sizeof(hkVector4);
        part.m_indexBase = meshShape->m_triangles.begin();
        part.m_indexStriding = sizeof(hkpSimpleMeshShape::Triangle);
        extendedMesh->addTrianglesSubpart( part );
    }
    hkpMoppCompilerInput mci;
    mci.m_enableChunkSubdivision = false;

    hkpMoppCode* code = hkpMoppUtility::buildCode( extendedMesh ,mci);
    hkpMoppBvTreeShape* moppShape = new hkpMoppBvTreeShape(extendedMesh, code);
    code->removeReference();
    extendedMesh->removeReference();

    hkpRigidBodyCinfo info;
    info.m_friction = 10;
    info.m_shape = extendedMesh;
    info.m_motionType = hkpMotion::MOTION_FIXED;
    info.m_position = position;
    info.m_rotation = hkQuaternion(hkVector4(0,1,0),0);
    hkpRigidBody *r=new hkpRigidBody(info);
    m_world->addEntity(r);
    return r;
}

int DrawRigidBody(hkpRigidBody *rbody,hkVector4 &color)
{
    if(!rbody)return 0;
    const hkpShape *shape=rbody->getCollidable()->getShape();
    hkTransform t=rbody->getTransform();

    hkpShapeDisplayBuilder::hkpShapeDisplayBuilderEnvironment env;
    hkpShapeDisplayBuilder GeometryBuilder(env);
    hkArray<hkDisplayGeometry*>* displayGeometries;

displayGeometries = new hkArray<hkDisplayGeometry*>;
GeometryBuilder.buildDisplayGeometries(shape, *displayGeometries );

    for (int j=0; j<displayGeometries->getSize(); j++)
    {
        hkDisplayGeometry* geometry = (*displayGeometries)[j];
        geometry->buildGeometry();

        hkGeometry* mesh = geometry->getGeometry();
        if(!mesh)exit(0);
        //OpenGlRendering(mesh,t);        //rendering using opengl....
        geometry->removeReference();
    }
    delete displayGeometries;

return 1;
}

void InitHavok()
{
    //other code...
    car=CreateMesh(hkVector(0,0,0),0.05);
}

void Render()
{
    //othercode...
    DrawRigidBody(car,hkVector4(0,0,1));
}

方法二：直接获取aabb盒画线

hkpRigidBody *rb = xxx;

hkAabb aabbOut;

const hkpShape *pShape = rb->getCollidable()->getShape();

pShape->getAabb(rb->getTransform(), 0.0f, aabbOut);

//根据shape类型可以设置不同的颜色

hkpShapeType type = pShape->getType();

// 。。。。。。

//接下来就是根据hkAabb画线 aabbOut.m_min和aabbOut.m_max