To create a smooth acceleration on a spaceship, I use the applyForce function in every call of the “scene.registerAfterRender” loop, then I find a confusing decline on the LinearVelocity of the physicsImpostor.

I console.log() the “physicsImpostor.getLinearVelocity()” in each second here(the PhysicsImpostor’s mass and the force on z axis are both 1):

e {x: 0, y: -1.7879269573660925e-16, z: 0.9125334900243433}

e {x: 0, y: -2.0474306752575292e-16, z: 1.898483115518114} 0.9859496254937709

e {x: 0, y: 7.687377465365088e-17, z: 2.793606566177473} 0.8951234506593588

e {x: 0, y: 9.017056831196015e-16, z: 3.7767822344174657}

e {x: 0, y: 2.254228929525085e-15, z: 4.654680743052351}

e {x: 0, y: 4.594690234244627e-15, z: 5.6189370724315015}

e {x: 0, y: 7.730882187086167e-15, z: 6.511102152418256}

e {x: 0, y: 1.226615830650276e-14, z: 7.456486442117993}

e {x: 0, y: 1.7859625194924394e-14, z: 8.346461686068256}

e {x: 0, y: 2.4448979779180875e-14, z: 9.182453949402253}

e {x: 0, y: 3.336708286547252e-14, z: 10.100681766516667}

e {x: 0, y: 4.336647649617383e-14, z: 10.950259590319394}

e {x: 0, y: 5.599786948828297e-14, z: 11.850516219409066}

e {x: 0, y: 7.077403207272746e-14, z: 12.74162100466624} 0.8911047852571734

e {x: 0, y: 8.754497849525879e-14, z: 13.609279755013596} 0.8676587503473563

e {x: 0, y: 1.0565950915960372e-13, z: 14.425517535689757} 0.8162377806761612

e {x: 0, y: 1.2715472937687262e-13, z: 15.276337320726881} 0.8508197850371246

As you can see,the force’s acceleration effect become weaker and weaker，After a long time the LinearVelocity will infinite proximity 100.

I had tried CannonJSPlugin and AmmoJSPlugin,both of them has the same problem,could I find a way to handle it?