我的游戏使用 box2dweb。我在一个圆圈周围放置了四个盒子，并给了圆圈一个初始速度。我预计圆圈会从墙上弹开，但碰撞后圆圈会与墙平行移动。只有当圆移动缓慢时才会发生。圆最后总是停在墙上。如何使圆的行为正确？下面的脚本显示了问题。
<!DOCTYPE HTML>
<html lang="ja-JP">
<head>
<meta charset="UTF-8">
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript" src="http://jsdo.it/Kon/box2dweb/js"></script>
<script type="text/javascript">
var Ball_Speed = 2.0;
var b2Vec2 = Box2D.Common.Math.b2Vec2;
var b2Body = Box2D.Dynamics.b2Body;
var b2World = Box2D.Dynamics.b2World;
var b2CircleShape = Box2D.Collision.Shapes.b2CircleShape;
var b2DebugDraw = Box2D.Dynamics.b2DebugDraw;
$(function(){
"use strict";
var canvas = $("#canvas");
canvas.css("width", 500);
canvas.css("height", 500);
canvas.get(0).width = 500;
canvas.get(0).height = 500;
var world = new b2World(new b2Vec2(0, 0), true);
var debugDraw = new b2DebugDraw();
debugDraw.SetSprite(canvas.get(0).getContext("2d"));
debugDraw.SetDrawScale(100);
debugDraw.SetFillAlpha(0.9);
debugDraw.SetLineThickness(1.0);
debugDraw.SetFlags(b2DebugDraw.e_shapeBit | b2DebugDraw.e_jointBit);
world.SetDebugDraw(debugDraw);
var fixDef = new Box2D.Dynamics.b2FixtureDef;
fixDef.restitution = 1;
var bodyDef = new Box2D.Dynamics.b2BodyDef;
bodyDef.linearDamping = 0.2;
// Create Wall //////////////////////////////////////////////////////////////////
function createWall(x, y, w, h){
bodyDef.type = b2Body.b2_staticBody;
bodyDef.position.x = x + w / 2;
bodyDef.position.y = y + h / 2;
fixDef.shape = new Box2D.Collision.Shapes.b2PolygonShape;
fixDef.shape.SetAsBox(w / 2, h / 2);
world.CreateBody(bodyDef).CreateFixture(fixDef);
}
createWall(0, 0, 2, 0.1);
createWall(0, 0, 0.1, 2);
createWall(2, 0, 0.1, 2);
createWall(0, 2, 2, 0.1);
// Create Ball
fixDef.shape = new b2CircleShape(0.2);
bodyDef.type = b2Body.b2_dynamicBody;
bodyDef.position = new b2Vec2(1.5, 1.0);
bodyDef.linearVelocity = new b2Vec2(Ball_Speed, Ball_Speed);
world.CreateBody(bodyDef).CreateFixture(fixDef);
(function loop(){
world.Step(1 / 60, 10, 10);
world.DrawDebugData();
world.ClearForces();
setTimeout(loop, 15);
})();
});
</script>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
</html>
最佳答案
尝试将 Box2D.Common.b2Settings.b2_velocityThreshold 的值更改为零。
http://www.iforce2d.net/b2dtut/gotchas#slownorebound
关于javascript - box2dweb : Walls don't bounce a slow object，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12317040/