@Elvisish I did a bouncing ball that moved in 3d using the inbuilt bouncing ball objects.
Basically the ball bounces in X,Y as one object, and in the Z as another object that just tracks the Y movement. This allowed me to have a ball that moved on all 3 axis using the inbuilt physics of Fusion 2.5.
I'm going to use a similar idea for bullet drop.
P3D was great but Firefly is a lot better as far as sheer performance is concerned. I enjoyed my time with P3D but it had limitations, its basically you get what you pay for. A very basic 3D program. If you did a simple dungeon crawler in it where the game was loaded in rooms P3D will work fantastic, same with FPS, if you were just doing a Wolf3D clone P3D works fine (actually better than fine since it allows you to look up and down as well as move up and down stairs). That said though P3D is actually harder to use versus Firefly. Firefly just uses an object for each type of module, whereas P3D uses a qualifier which isn't as nice. P3D is better for UI at this stage because you can position actives over the top of the render frame whereas Firefly at the moment has to always be on top (though CT is adding new objects to the engine exclusively for UIs).
If I had to compare Firefly all the way because Polygons are amazing. P3D is great but it can't do polygons well unless you reduce the amount that are rendered on the screen.