cocos-engine/tests/physics/stability.ts

import { Vec3 } from '@base/math';
import { physics } from '../../exports/physics-framework';
import { Node } from '../../cocos/scene-graph';
import { director } from '../../cocos/game';
import { PhysicsTestEnv } from './physics.test';

export default function(env: PhysicsTestEnv) {
    describe(`Stability test`, () => {
        test.each([1, 0.5])(`Stable %s`, (v) => {
            doTest(env, 500, v);
        });

        if (env.backendId === 'physx') {
            test.each([0.25, 0.15])(`Stable for small scale in PhysX %s`, (v) => {
                doTest(env, 500, v);
            });
        }
    });
}

/**
 * This function is used to test stability of the physics
 */
function doTest(env: PhysicsTestEnv, steps = 500, scale = 0.5) {
    const { rootNode: parent } = env;

    const nodeStatic = new Node('StaticB');
    parent.addChild(nodeStatic);
    nodeStatic.addComponent(physics.BoxCollider);
    nodeStatic.worldScale = new Vec3(20, 0.01, 20);
    nodeStatic.worldPosition = new Vec3(0, -0.005, 0);

    const size = new Vec3(scale, scale, scale);
    const X = 8, Y = 8, Z = 4;
    let x = 0, y = 0, z = 0;
    for (let i = 0; i < Y; i++) {
        y = size.y / 2 + size.y * i;
        const CX = X - i;
        for (let j = 0; j < CX; j++) {
            x = CX * -size.x / 2 + j * size.x;
            for (let k = 0; k < Z; k++) {
                const nodeDynamic = new Node(`${i}-${j}`);
                parent.addChild(nodeDynamic);
                nodeDynamic.worldScale = size;
                nodeDynamic.worldPosition = new Vec3(x, y, z + k * size.z * 2);
                nodeDynamic.addComponent(physics.RigidBody);
                nodeDynamic.addComponent(physics.BoxCollider);
            }
        }
    }

    const dt = physics.PhysicsSystem.instance.fixedTimeStep;
    const bodies = parent.getComponentsInChildren(physics.RigidBody) as physics.RigidBody[];
    const middle = Math.floor(steps / 2);
    for (let i = 0; i < steps; i++) {
        if (i === middle) {
            bodies.forEach((v) => {
                v.wakeUp();
                expect(v.isSleeping).toBe(false);
                expect(v.isAwake).toBe(true);
            });
        }
        director.tick(dt);
    }

    bodies.forEach((v) => {
        expect(v.isSleeping).toBe(true);
        expect(v.isAwake).toBe(false);
    });
}