I not quite agree with the opinions that if you chose exclusive convention for defining rectangles or inclusive, or chose righthanded coordinates or lefthandet it in not to much important - this is important for at least two reasons
1) different conventions have different properties
2) it is easier to communicate if sides of communication have the same choices
so as to two things mentioned i chose inclusive and right-handed but
still I am not sure what scale to chose to descript a scene coordinates in 3d
there are probably two main options to chose
1) metric coordinates where 1.0 is 1 meter
2) other than metric, (i think for example about scale where 1.0 = 1 cm,
this has some advantake that this 1 as a cm is better for my scale of details
of the things - but has disadvantage that when using this numbers need to convert something like 23300 to meters (23.3) - so i really dont know, think that maybe metric can spare me a bit of headahe (?)
Has some person some opinion on that?