Collision Issue with bounce

[3Dlove]

Hello guys :-)

 

Here is the playground :

http://www.babylonjs-playground.com/#21NME5#1

 

When you walk toward the red wall, the engine make a bounce in back, due to the collision.

Thats not happen when you walk toward blue walls.

 

How to solve that ?

 

Thanks and have a nice day =D =D =D

[RaananW]

That's an a wonderful feature! Camera bouncing...

 

Well, the simplest (temporary) fix would be this - http://www.babylonjs-playground.com/#21NME5#2

 

I have no idea why that happens, but it is really interesting. Both small planes are causing this. Maybe try avoiding using planes (a box would actually work better at the bottom) until we inspect this.

[3Dlove]

Okay thank you,

 

I can't use your solution because I use a scene generated by Blender, so I will try with a cube

 

So, is it a bug ? =p

[RaananW]

no, not a bug. a feature 

[3Dlove]

Okay^^

 

I tried with a cube, but same issue :

http://www.babylonjs-playground.com/#21NME5#3

[RaananW]

seems like an issue with the mesh's position. 

http://www.babylonjs-playground.com/#1MIHVA

(look down, walk forward)

if you change the y position it is fine:

http://www.babylonjs-playground.com/#1MIHVA#1

 

With scaling it works as well:

http://www.babylonjs-playground.com/#1MIHVA#2

 

no time at the moment, i'll try debugging it later. anyone else is more than welcomed :-)

[3Dlove]

Seems like to depend of y height of object and camera ellipsoid :

I took your 1st example and change y ellipsoid : http://www.babylonjs-playground.com/#1MIHVA#3

 

That could be problematic for baseboard for instance :/

[GameMonetize]

Hello this is because the gravity is too strong for this scene:

http://www.babylonjs-playground.com/#21NME5#4

 

As the camera try to climb the small stair, the gravity generates an opposite vector which is too powerful

[RaananW]

As I said, a feature :-)

[Vousk-prod.]

"gravity is too strong" sounds strange to my ears...   

The scene in the PG is 50 units wide, and in the engine, gravity is set to -9.807 in Y.

Since earth gravity is 9,807 m/s², we can consider that for physic calculations, meter is the default unit in BJS.

So for this particular scene, designed at "human scale", the gravity should be the right one, and not "too strong". Am I missing something ?

[GameMonetize]

I've just analyzed the result (debugging in the PG) and I saw a gravity value of 122

 

But it was actually a bug that Raanan fixed like a boss

[Vousk-prod.]

Yep!

 

For future readers, explanation in this post : http://www.html5gamedevs.com/topic/17709-free-camera-collision-problem-with-mesh/

[Myjestic]

Hi,

same problem here on BJS 3.0.

How can I get rid of this bounding effect. In the PG @Deltakosh posted http://www.babylonjs-playground.com/#21NME5#4 , he inserted

scene.gravity.y /= 100;

For me this is not an option, because if you look to the ground and walk backwards you will fly up.

If I increase the height of the step (mesh) it will work. But is there another possibility?

[RaananW]

How about just reducing it to /10? or /20 ? Seems like it reduces the bouncing effect, and you don't fly high when going backwards

[Myjestic]

I tried that already. If I reduce to 10 or less, bouncing is reduced but I can "fly" away.

Tried it here. Just walk against the box. https://www.babylonjs-playground.com/#4HUQQ#206

Any other suggestions?

[Myjestic]

Hey @RaananW any other approches for this issue?

From another topic @Deltakosh wrote this problem is fixed.

On 8.10.2015 at 5:02 PM, Deltakosh said:

Yep my fix was the wrong one. Raanan found the issue we introduced with 2.1

 

It is now fixed

I can't get around this problem. It is not an option for me to reduce the gravity or increase the height of the camera ellipsoid.

BJS "thinks" this is a stair. Can I disable this behaviour?

[RaananW]

Wow, that's a quote from 2015!

I guess it was fixed back then. Probably by me if DK said so...

You can increase the scene's gravity to avoid the "flying" behavior. You could force the ellipsoid of the object to be bigger just to not walk on top of it. You could run a beforeRender loop, forcing the person to always have a static y position (no idea if this would really work).