# Real-life units - 3D-math

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Hi! Could anyone explain me how to convert real-life units into "computer-readable" units? Say I want to accelerate a car with 5 m/s. Everywhere I read something like this: vel = vel += 0.5f But how do I define to x.xf be something like xxx Meters? Other scenario: I create a 3d-building using Maya or whatever. Let it's height be 35.0f or something like that. Now what do I need to do if I want this building to appear ingame as a 50 Meter high building? I'm totally lost here :( regards

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Think for a moment. What does it mean to measure 50 meters? Measuring something is a human action: putting a value and an unit on a given property by comparing it to a reference, the value of which is arbitrarily decided on.

So, simply decide that a line between (0,0,0) and (1,0,0) is a one meter long reference, and build everything according to that reference. This will make everything consistent.

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I too usually choose a 1 unit as 1 meter, not sure if it's the best thing to do for large scenes tho. dont worry when you're building your model, just build it however you feel comfortable and provide a scale matrix with it to get it to the dimensions you want.

Tim

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Great, thanks guys!

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