Firemonkey 3d Measurement Units

[Eric Bonilha 3]

Hello

 

Sorry if this is a stupid question, but I was wondering, when using Firemonkey 3d objects in a scene, what is the measurement unit of object positions and dimensions?

I see for example, I can create a TPlane and set a width of 10 and height of 10, but that doesn't mean anything for me if it doesn't translate to a real measurement unit like meters?

 

In my case, I want to create a plane (lets say, a floor) that is 10x10 meters (in real world measurements) and place a camera object that is 4.5 meters high. How would I translate this measurement unit to whatever unit FMX 3d uses?

 

Thanks

[Vincent Gsell 9]

Hi

No stupid question. 

 

FMX Real world measurement : There are not. You decide. 🙂

 

It is a matter of scale.

 

In your example, for a room/floor, you can *arbitrary* fix 1 FMX unit for 1 meter, for example.

 

So, in this case, you will working in your 3d FMX project in meter. The Proportion will alway be correct, whatever the real world unit you will apply.

 

As a side effect or working with scale, we can note : 

--> Real world unit will be important when you will have to convert potential import/export 3d object to your/anoter coordinate (scale) system.
for exemple, taking a turbosquid (or whatever) object and import it into your "world", will lead you to put, after loading, a code such as :
MyImportedObject.Scale.point := point3d(lConversion,lConversion,lConversion);

 

--> In fact, depending what project you are modelizing ("human" scale (as your exemple), molecular scale, maps (GIS) Scale or event inter-planetary space scale) you will have to adapt FMX unit scale to your target world normal metrics (and vice-versa).

 

--> Technical tips : FMX 3D allow you 1000 unit of camera visibility, so, if you want to modelize a "city" map, for exemple, you'll certainly fixed a scale such as 0.001 FMX unit for 1 meter irl, for exemple.

 

Hope this help
 

[Eric Bonilha 3]

Thank you very much

 

Indeed, if I consider everything as meters it works like a charm, exactly how I needed

 

Thank you very much for the explanation