Standard unit value for 3d game character height?

Question

Basically I'm building a first person shooter game using DirectX9. And now, I'm working on the modeling side. But before I start modeling, I have to make sure that I create all the models with accurate size. So it doesn't look too big or too small in the game. But I'm having problem deciding the characters height value including the main character and the NPC characters. I think it would be easy to measure other models/houses/walls/doors size if I have the characters height. Otherwise, I will messed up everything.

I assume that all the characters are 1.8 meter in height, including the main one. Though not sure that how to represent that value in DirectX vector ( DirectX unit == ? ) but If I set the camera height that value, it looks too low from the ground ( in my eyes ). Now what is the next value? Should I switch to fit? Which would very big value like 6. Or is there any standard value for that case which I don't know?

I hope you guys have understand my situation. Actually I'm very new to this kind of stuffs. So hopping to get some help or suggestion which would be great for me.

Answer 1

There is no "standard," although for reasons of numerical stability you will want to choose some conversation factor between modeling and rendering units that keeps them small (don't make characters 10,000,000 units tall, prefer to make them more like 1 to 10 units tall).

Pick values that work for you, your pipeline, and your game. This means adjusting the modeling units (maybe on export) or rendering units (by adjusting projections and whatnot) accordingly until you find a balance that makes sense for your game and how you think about the problems space.