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

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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?

Answer 1

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Answer by Sondre-S · Jun 22, 2016 at 10:41 PM

The correct answer is this:

when exported as .dae the model is much bigger and you must use 0.0254 as scale factor in Unity.
when exporting as FBX but in inches, the correct scale factor is also 0.0254.
when exporting as FBX, (requires Sketchup Pro), you need to use scale factor 1 to get the correct size in Unity.
there is a fourth option that I haven't explored, which is using feet & inches in Skp and exporting as .dae.

When I say correct scale I mean "true scaled". 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.

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guneyozsan · May 21, 2017 at 01:08 AM 2

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

Sondre-S guneyozsan · May 10 at 01:41 PM 0

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Thank you :)

Answer 2

Answer by Hatdatsat · Nov 28, 2018 at 08:06 AM

@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.

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Answer 3

Answer by tanoshimi · Jun 21, 2016 at 08:46 PM

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.

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Sondre-S · Jun 23, 2016 at 02:30 PM 1

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

guneyozsan · May 21, 2017 at 01:02 AM 2

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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. $$anonymous$$ost obvious one is that you will get huge triangular shapes on the shadow edges.

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

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