FtD Script Notes

ZerothAngel's FtD Script Notes

Ultimately, I write these scripts for myself. Half of my enjoyment in these types of games (From the Depths, Space Engineers) is programming the behaviors and systems.

Also, I don't normally do code requests, but I'm open to interesting ideas, especially ones that I'd eventually use myself. (The dumb-fire rocket controller and smart mines are recent examples.)

Having said that all that, here are some notes on how my scripts are used and their likely limitations.

What Scripts I Use Regularly

Or: What can be considered relatively bug-free.

Unfortunately, I don't get much feedback from other people. What I write is generally well-tested on my own designs. I'm sure for other people, if something of mine doesn't work near perfectly out-of-the-box, they drop it without a complaint. So I don't hear of problems.

I pretty much regularly use all scripts that I have listed on my public page. But there's a handful of exceptions, and you should be wary about using them as well:

• airplane — This is still too new, and I have no airplane design of my own. I have been testing with the SD Wyvern, SS Retribution, and a workshop plane. All but the Retribution are just "aerodynamic bricks" — they don't actually have any lift. So something to be aware of.
• multiprofile — Though I use this regularly (it's now my standard missile script), I don't use the weapon slot or direction selectors at all.
• rocketcontrol — Created this due to a request, but I don't use it myself.

Thrusters

The Lua binding for thruster control, I:RequestThrustControl, runs all thrust requests through some sort of propulsion balancing. So if one facing does not have perfectly balanced jets on both sides of the CoM, they will not fire (because it would induce a rotation).

This isn't ideal and causes problems especially if you don't build symmetrically or if thrusters get damaged.

This is why I tend to favor quadcopters and dediblade-based airships.

A workaround is to use a complex controller key to trigger jets. A downside is that this key would no longer be available for manual usage. However, there are quite a number of complex controller keys (around 14 or so), so it shouldn't be much of a problem.

Additionally, since axes are often related (e.g. altitude/pitch/roll use upward-/downward-facing jets), jets can be reduced to using a single key.

See the APRThrustHackKey, YLLThrustHackKey and ThrustHackKey options of appropriate scripts.

Control Axes

With recent versions of FtD, almost every component has the freedom to listen on one or more control axes (e.g. "hover", "yaw", "main", "A", etc.) This is very flexible!

Unfortunately, Lua can only control a small subset (via I:RequestControl): Yaw, Pitch, Roll, Main. (And Lua can only read a different subset: Main, Secondary, Tertiary.)

So true hybrid control systems are still out of reach. What's more, the old drive maintainer axes (now called STIM Primary, STIM Secondary, STIM Tertiary) seem to be deprecated, which is unfortunate since those axes could be fully read & controlled by Lua. (Though inexplicably, you could not assign them to dediblades, which limited their usefulness.)

With all that said, it is probably best to use standard control axes (e.g. set ControlFractions to 1 for everything). But this is only feasible if your ship does not hover or strafe.

Otherwise, use 1's where appropriate in JetFractions and SpinnerFractions and zero-out ControlFractions where necessary.

Missiles

I'm typically pretty conservative with my missiles. I often hear talk about monstrous 8- or 10- block long missiles.

I usually just stick with 6 blocks or less. So my missiles are just a tad more maneuverable and that's what the phase distances in my scripts are tuned for.

Yaw

The yaw PID of my scripts is typically undertuned. It seems to be common nowadays to stack multiple rudders and such.

You will typically benefit from increasing Kp for the yaw PID. (I usually use around 3.75 for single rudder designs and scale appropriate for designs with 2 or more.)

Just remember: assuming any sort of "evasion" is off, if your vehicle oscillates too much while attempting to go in a straight line, you will have to lower Kp.

You may also be interested in my yawtest script to help in tuning, which, while moving forward at various speeds, rotates the vehicle every 90 degrees every minute or so. It also outputs informative stats like turning radius and turning time.