Useful tips and tricks


Skinned mesh

You should use only a single skinned mesh for each character. The rendering time for a model could roughly double as a result of using two skinned meshes in place of a single mesh and there is seldom any practical advantage in using multiple meshes.


Use as few materials as possible You should also keep the number of Materials on each mesh as low as possible. The only reason why you might want to have more than one Material on a character is that you need to use different shaders for different parts. However, two or three materials per character should be sufficient in almost all cases.


Use as few bones as possible. A bone hierarchy in a typical desktop game uses somewhere between 15 and 60 bones. The fewer bones you use, the better the performance will be. You can achieve very good quality on desktop platforms and fairly good quality on mobile platforms with about 16 bones. Ideally, keep the number below 30 for mobile devices, and don’t go too far above 30 for desktop games.

Polygon count

The number of polygons you should use depends on the quality you require and the platform you are targeting. For mobile devices, somewhere between 300 and 1500 polygons per mesh will give good results, whereas for desktop platforms the ideal range is about 1500 to 4000. You may need to reduce the polygon count per mesh if the game has lots of characters on screen at any given time.

Changing Position, RotationAngle or Scale

Changing one of the transformation settings or visual properties of a 3D scene object initializes rendering implicity. So, when you're manipulating more than one object or property this could lead to very bad performance.

Therefor we need some way of grouping those operations and to prevent FMX from updating each time.

Due to that, GorillaViewport provides the BeginUpdate() and EndUpdate() methods. Encapsulate your transformations to increase performance.

procedure TForm1.Timer1Timer(Sender: TObject);
    GorillaCube1.RotationAngle.Y := GorillaCube1.RotationAngle.Y + 5;
    GorillaSphere1.Scale.Point := GorillaSphere1.Scale.Point + Point3D(0.1, 0.1, 0.1);


It is not uncommon to use a thread to compute visual property values. But because FMX (and also Gorilla3D) only runs in main thread, we need to synchronize somehow.

Synchronization needs to be threadsafe, so everyone uses TThread.Synchronize(nil, DoSync) inside of its thread. That's okey for many applications, but the better way is to use messaging or TThread.Queue(nil, DoSync) for this job.

While “Synchronize” blocks the application to force updating with main thread, “Queue” instead updates the app when there is time for. For further information take a look at:


You may have noticed, in some demos / apps debugging slows down mouse and keyboard inputs.

Please read more about this issue, here: