Here is a brief guide to the FIN feature and finforce variable in Reassembly game. this guide will help you to find FIN feature and how to use it.
The FIN in Reassembly is very simple in terms of its physics simulation: it creates drag along a single axis, that being the horizontal one relative to the block’s facing direction. This means that fins can move forward and backward without issue, but encounter significant resistance moving left or right. This effect may be more technically referred to as “anisotropic friction”.
An easy way to think about this is to imagine the missile or spaceship as a car, viewed from above. The fins, which can be thought of as “wheels”, have no friction when moving forward or backward, because they roll. However, they have lots of friction left-to-right, which is why you don’t slide off the road every time you turn.
On the other hand, ship parts with FIN attached can also be handy. If you don’t like your ship drifting left to right you can use fins aligned to your ship’s facing direction to keep them under control. The benefit of having ship parts with FIN components is that they can be rotated to any desired direction, allowing you to control exactly which axes of movement your ship resists, and which ones it smoothly coasts through. Placing the fins on different parts of the ship also allow for interesting controls. For example, putting them at the back, aligned to the ship’s facing direction, causes the back of your ship to experience drag while drifting. Similarly to a real-life rocket, this causes the ship’s nose to yaw toward the direction it’s actually moving in. Many other combinations exist.
A fin’s drag force is decided by the variable *finForce*. Like most other physics-based numbers, it can be difficult to know exactly what the number represents, so you’ll have to experiment. In my experience, a finForce of 10.0 was sufficient to significantly decrease drifting in a missile with a mass of 6.0. When using the fins to control a ship’s drift, I found significant sideways drag using two fins, each with a finForce of 1,000,000. With sufficient finForce, you can actually drive a ship almost exactly like a battle tank, able to turn in place but not prone to drifting sideways.
I should also talk about negative finForce. The update log claims that negative finForce acts as drag. I presume this to mean it’s supposed to exert drag in all directions. However, any time I try to incorporate negative finForce into my mod files, the game freezes upon loading the save game (not completely, the cursor is still movable and visible, and Windows doesn’t recognize it as Not Responding, but ships don’t move, camera doesn’t follow mouse, and no controls respond, including the X at the top right of the window to close the game). I’ll update this log as soon as I find out what’s wrong, or if it’s a bug, as soon as it’s fixed.