Why UPS update slowly?

[Joh]

I use UPS () to calculate the exact movement of a body (GetBodyVelocity / UPS() ) but it seem to update "slowly", almost 1 update to 1/2 second, why?

[Canardia]

You should use AppSpeed() for entity movements.

[Joh]

What AppSpeed() return exactly?

I saw that dividing by UPS() i receive EXACTLY how many space the entities move..

[Canardia]

AppSpeed() returns the number 1.0 adjusted to the speed of the program. So on heavier scenes the number 1.0 could be 1.2 or more.

[Joh]

I am sorry but how this could help me?

If i set the velocity to 50 it will move 50 in one second so exactly 50/UPS()..

How this appspeed can help me in this way? I'll need to know how much the entity is moving in a loop.

[Canardia]

Ah nm, you are using physics bodies, then you don't need AppSpeed().

[Joh]

Yeah sorry, i am using bodies.

So do you know how can i do for UPS? Is UPS = FPS? I got it in mind right now if it is i can calculate the FPS and use that..

[Canardia]

Physics movement has really nothing to do with FPS or UPS. It has only to do something with time, so you can check how much a body has moved with something like this:

double vtimer=clock()+1000, vcount=0, vcur=0, vpersec=0;
while(){
vcur=Length(GetBodyVelocity(body));
vcount+=vcur;
if(vtimer<clock()){
	vtimer=clock()+1000;
	vpersec=vcount;
	vcount=0;
}
DrawText(1,100,"speed per second=%f",vpersec);
}

[Joh]

mmm well in some way it have to do with UPS (Update per Second) check this:

 

C: TVec3 CalcBodyVelocity( TBody body, TVec3 &position, flt smoothing=1 )

Lua: CalcVelocity:TVec3( position, smoothing )

Calculates the velocity required to make the body reach the specified position in one second, with no damping. This can be used for precise control of body movement.

 

Also in the example he use Flip (1) and use 60 (flip 1 should fix the UPS to 60)

SetBodyVelocity(body,t.scale(60.0))

So i am pretty sure it have something to do with it..

 

Anyway i'll check your way too.

[Canardia]

No it hasn't. You should never use Flip(1), but always Flip(0), since on different machines Flip(1) might not even work (if the user has force sync=off). Flip(0) quarantees that your program runs with the same speed on all machines (with AppSpeed() for non-physics movements). Flip(0) makes also the application run faster than Flip(1), regardless of the FPS. You can see this especially in heavy scenes where the FPS is less than 20.

John Carmack also said that you should never use vsync, but always time-based sync.

[Joh]

Nice infos.

Thx.