接下来我们增加更多的模型来丰富三维场景,我们可以设置mass属性为0,这意味着这个模型质量为0,会参与碰撞而自身位置不会产生变化。这样会形成类似于变化“地形”的效果。
pos.set( 0, 1.2, 0 );
quat.setFromAxisAngle( new THREE.Vector3( 0, 0, 1 ), 30 * Math.PI / 180 );
var obstacle = createParalellepiped( 10, 1, 4, 0, pos, quat, new THREE.MeshPhongMaterial( { color: 0x606060 } ) );
obstacle.castShadow = true;
obstacle.receiveShadow = true;
接下来我们写个简单的循环,随机生成更多的三维模型。
for (var i = 0; i < 20; i++) {
pos.set(Math.random() - 10, 2 * (i + 1), Math.random() + 10);
quat.set(0, 0, 0, 1);
createParallellepiped(1, 1, 1, 1, pos, quat, createRendomColorObjectMeatrial());
}
这里存在两类模型,刚体和柔体,会在物理引擎下运动,真实模拟一个物体在现实世界中受到力后的行为。
上面我们添加的模型都是刚体,刚体碰撞自身形状不会发生变化,而柔体会在受到外力的时候发生变形,产生类似气球的效果。
添加柔体模型:
var boxGeometry = new THREE.BufferGeometry().fromGeometry( new THREE.BoxGeometry( 1, 1, 5, 4, 4, 20 ) );
boxGeometry.translate( -2, 5, 0 );
createSoftVolume( boxGeometry, volumeMass, 120 );
function createSoftVolume( bufferGeom, mass, pressure ) {
processGeometry( bufferGeom );
var volume = new THREE.Mesh( bufferGeom, new THREE.MeshPhongMaterial( { color: 0xFFFFFF } ) );
volume.castShadow = true;
volume.receiveShadow = true;
volume.frustumCulled = false;
scene.add( volume );
textureLoader.load( "textures/colors.png", function( texture ) {
volume.material.map = texture;
volume.material.needsUpdate = true;
} );
// Volume physic object
var volumeSoftBody = softBodyHelpers.CreateFromTriMesh(
physicsWorld.getWorldInfo(),
bufferGeom.ammoVertices,
bufferGeom.ammoIndices,
bufferGeom.ammoIndices.length / 3,
true );
var sbConfig = volumeSoftBody.get_m_cfg();
sbConfig.set_viterations( 40 );
sbConfig.set_piterations( 40 );
// Soft-soft and soft-rigid collisions
sbConfig.set_collisions( 0x11 );
// Friction
sbConfig.set_kDF( 0.1 );
// Damping
sbConfig.set_kDP( 0.01 );
// Pressure
sbConfig.set_kPR( pressure );
// Stiffness
volumeSoftBody.get_m_materials().at( 0 ).set_m_kLST( 0.9 );
volumeSoftBody.get_m_materials().at( 0 ).set_m_kAST( 0.9 );
volumeSoftBody.setTotalMass( mass, false )
Ammo.castObject( volumeSoftBody, Ammo.btCollisionObject ).getCollisionShape().setMargin( margin );
physicsWorld.addSoftBody( volumeSoftBody, 1, -1 );
volume.userData.physicsBody = volumeSoftBody;
// Disable deactivation
volumeSoftBody.setActivationState( 4 );
softBodies.push( volume );
}