Correct scale factors for Skp models (Metric vs Imperial and .dae vs .FBX) [Solved]

For some reason I use meters in Sketcup, not inches, and I’m using the built in FBX exporter in Skp Pro, what scale factor should I use? When exporting as dae I used a scale factor of 0.025 but what scale factor should I use when exporting directly?

3 Answers

3
  • when exported as .dae or as FBX but in inches, you should set scale factor to 0.0254 in Unity.
  • when exporting as FBX, (requires Sketchup Pro), you need to use scale factor 1 to get the correct size in Unity.

1 unit in Unity = 1 meter, so if a car is 4.5 meters long in the real world, it should be 4.5 units long in Unity.

Actually the precise scale factor is 0.0254 (meter to inches).

If you want the questions to update on the fly like that, then they have to exist somewhere outside the instructor's device where others can get them. Of course the ingame editor could have an upload functionality.

@tanoshimi you cant just use anything you want for a unit. It is linked to more than just gravity, just try using ar or vr.

Very true. Thank you. It would have to upload to a server using a sql database?

What kind of database would i use to store User input from the application?

You can use anything you want. As a game engine rather than architectural modelling tool, Unity doesn’t care what unit of measurement you use. A 1 unit cube is just that - 1 unit.
The only thing to be aware of is if you’re using Physics you will have to adjust gravity and other forces to match the scale you use. The default gravity of 9.81 assumes 1 Unity unit = 1m.

@tanoshimi I assume most Unity users want their models to be true scaled. You don't really answer the question.

Unfortunately if you don't use correct scale within Sketchup you will get wrong scales for normals and tangents which will result incorrect light and shadow resolution. Most obvious one is that you will get huge triangular shapes on the shadow edges.