System Unit Scale

[t888eddy]

If I want to create a big project with houses and each house to have very small objects, which option should I use from the System Unit Setup dialog? I mean that I have a very, very big area, several square kilometers and I also want to place some houses and inside them I want to have small, but detailed objects. Thanks in advance for the answer!

[Alfred.DeFlaminis · Accepted solution]

Hello @t888eddy,

System unit scale can seem tricky at first, but we have a Youtube video here that goes into detail about picking the right units and details more information about unit setup.  I hope you find it informative!

You can also find some general guidelines about usage and a more in-depth description of system units here.

Please hit the "Accept as Solution" button if my post fully solves your issue or answers your question. This lets me know that I was effective in helping you, and thank you for doing so.

Best Regards,

[t888eddy]

Actually, I saw the video just before posting and I found it very useful, but I want just an opinion: what should I choose there if I have a big scene, say 10 square kilometers, but with a lot of tiny details?

[Alfred.DeFlaminis]

Hello @t888eddy,

I'll do my best to answer your question but it's tough to answer this with 100% accuracy.  Generally speaking you only need what the camera sees (or is reflected) for high end rendering , so it's difficult without knowing if you plan on importing it into a game engine or rendering with a high end renderer like Mental Ray or Vray in Max.  It's a bit hard to imagine a fully populated city with interiors and exteriors at the same time, at least from a performance/RAM perspective. 

If I was a TD on the project for high end rendering, I'd ask for proposed camera shots so I knew how small exactly the details were meant to be, and then I'd likely have 2 versions of the file.  One version for rendering inside, and one for rendering outside. For games, I'd utilize as much texture detail as possible to make my city something that doesn't bog down the engine too much, and even then loading areas might be a necessity with lots of interior detail. 

Having said all that, I would shoot for meters and see how it goes.  Just know that a pencil shaving on the desk inside the house may not cast proper shadows or might have some rounding errors/distortions due to the scene scale.  Similarly, if you set it to say centimeters, some of the buildings might not appear perfect, especially as they get further and further from the origin. 

The good news is that you can always import your city into a new scene with different system units if problems appear.  You may have to scale the world (referenced in my 1st post above) but in the end you're not stuck with your decision should things get hairy for some reason. 

Best Regards,

[t888eddy]

I want to make some high renderings with MentalRay and also some videos, like walkthroughs. Not interested to put it in a game. So meters will be the starting option.

[Alfred.DeFlaminis]

Hello @t888eddy,

Sounds good!  Wishing you the best and happy Maxing!

Best Regards,