dimensions in the World

[jerome]

Hello,

 

I'm about to complete the port of my prototype from threejs to bjs.

I read the wiki about position and rotation but there is still a piece of information I need :

 

What do the dimension values represent ?

 

I thought they were pixels :  a box sized 10x10x10 would have been 10 pixels each size if the cam were set at the same position.

 

But viewing tuto video chapter4 about materials, I saw DK set a sphere (diameter = 2) at position.y = 1

and this sphere looked quite "big" (meaning it was displayed with many many vertices, many many pixels)

 

So what do this "1", this "2" represent ? Is there somewhere an equivalence ? to what ? meters, screen resolution ?

[RaananW]

The size is never pixels (if you are referring to real/screen pixels), it is 2 "units" in your world. Setting a box with diameter 2 and standing 2 "units" away from it will look the same as a box with 0.2 diameter when standing 0.2 "units" away from it. Those are not pixels.

 

I am saying "units", as it can reference meters (if your models are in meters) or cm, or inches, or any other measurement unit, it depends on the person who made the object (or you :-) ). Maybe someone else has a better name for it.

 

Also, the fact that a box looks big, does not actually mean it is made from more vertices (in this case, more pixels would be correct, if referring to real screen pixels). The number of faces/vertices stays the same.

[jerome]

So we are in a real infinite world ?

I mean : there is no elementary or unitary restriction ?

 

zero is zero, right.

 

But, something sized 0.0000000000001 could ever been displayed by dozen of pixels if I were standing close enough to it. Am I right ?

[RaananW]

i wouldn't try setting positions/dimension using such a small number, but using the correct configuration you can make it happen.

[jerome]

thank you for the answer :-)