[1.8.1] Docking Port Alignment Indicator (Version 6.8.5 - Updated 12/14/19)

[gilflo]

About orange circle

If you want this to be easier, once you have set as target the dock you want to dock, jump to the targeted ship ( use the control that allow to jump to the next ship near yours) and move this ship towards your ship, supposing your dock is at the top of the ship). Once it's done, hit T to toggle ASAS so as the ship will maintain this position. Come back to your ship and it should be nearly aligned with the targeted ship.

Edited August 21, 2013 by gilflo

[HeadHunter67]

So just like WASD moves the crosshairs to line up with the orange circle, IJKL moves the crosshairs (and orange circle when aligned) to line up with the green lines. Correct?

Precisely! When you think of it as moving the crosshairs, rather than the "needles", it becomes intuitive. People who have difficulty with it are often thinking of moving the needles - really, you can't, because where they intersect is the actual location of the port. The crosshairs are just relative orientation, which is adjusted by using WASD to align the nose to the same plane.

[RoboRay]

Right, you follow the needles... you don't move them. The crosshairs are where you are now, while the needles (or orientation circle) are where you want to be.

[Mr Shifty]

So which way to move do the green lines indicate? If the vertical green line is left of the centre line, do I need to thrust to the left to move the crosshairs, or thrust to the right to move the green line back to the centre line? Same Q for the horizontal line.

This is what the yellow marker is for. You want the yellow marker to be on the same side of the center of the display as the green crosshairs. This indicates that you are moving toward the target.

[DrPastah]

My docking part is on the side of my ship and when I try to align the orange reticle with the main lines, the controls don't react as I they should. When I press A or D, the orange arrow just rotates around the main lines.

[RoboRay]

My docking part is on the side of my ship and when I try to align the orange reticle with the main lines, the controls don't react as I they should. When I press A or D, the orange arrow just rotates around the main lines.

Did you select Control From Here on the docking port?

[e-dog]

This has become seriously awesome since last time I checked it!

[Eskarina]

Thank you for this, this should come standard ingame.

[NavyFish]

7000 downloads! Thank you guys!

[Simplicity]

Just goes to prove we love your mod

[razark]

Thank you guys!

No, thank you.

[HeadHunter67]

Where the green lines cross is where you want the orange circle to be for a perfectly-aligned docking.

Looking at it this way, the required movement becomes intuitive.

While adding some modules to my space station today, I had an epiphany and I'm going to tell you all about it. Here is how you can use what I said before to accomplish very fast, perfectly accurate docking, at any angle, without the need for overcorrection or slow approach. You don't even need to do the old Manley normal/anti-normal rotation trick.

As usual, you'll do all the typical preliminaries - Match velocities with your target, set the camera to Chase Mode (essential), choose "Control from here" on the docking vessel's port, and target the chosen port on the target vessel. Then:

1) Using WASD, align your nose so that the orange crosshair is dead center in the window. You are now moving in a direction parallel to the target port.

2) Using Q and E, rotate the vessel to the desired roll angle. This will set the green needles to the proper orientation.

3) Here's the important part: Use IJKL to move the window's yellow prograde marker (not the one on the navball) over to the intersection of the green lines. Use H to thrust forward towards the target at a speed comfortable to your level of skill and actual distance to the target (the one in the window is the actual distance to the target port, rather than the center of the vessel).

4) As you approach, the green needles will inevitably move closer to the center of the orange crosshairs. Use IJKL to adjust the yellow prograde marker so that it remains centered on the intersection. (You are not wasting mono fuel here - you're simply cancelling out the necessary translation velocity from step 3)

5) When everything is dead-center, all that remains is to slow down at the proper time to ensure a soft docking (0.1 m/s works nicely).

I apologize to those who knew how to do this already, or who may have intuitively but unconsciously understood it. But seriously, I can now use this plugin to complete dockings faster than any autopilot - and in less time than it took me to write this post.

I hope I've helped someone to unleash the real power of this wonderful little plugin.

Edited September 1, 2013 by HeadHunter67

[NavyFish]

Thanks for posting that guide, HeadHunter. I've been fairly busy with other commitments lately, and thus the plans to produce a new tutorial video that thoroughly explains how to use the gauge have been delayed. Your instructions should help new users until then! I'm linking your post on the OP.

P.S. If anyone wants to make a tutorial video of their own, I'd be highly appreciative (I'd rather focus on coding anyhow ). All I ask is that you let me review it first before posting, just to double-check for accuracy.

Edited September 1, 2013 by NavyFish

[HeadHunter67]

It's amazing how simply thinking about the approach information in a different way lets the pilot turn a few simple graphical indicators into a powerful docking assistant.

When I stopped trying to move the needles (impossible, actually) and realized I had to move to the needles, docking became easy.

When I realized today that all it takes is to line that prograde indicator up to the intersection and keep it there? Docking became dead simple.

I don't think I'll ever need a docking autopilot again. I used this trick to accomplish a docking at a very atypical angle - which is good for those who can't exactly rotate a big station to orbit-normal.

[Mr Shifty]

Yeah, thanks for that post HeadHunter. Those of us who had used similar indicators before dropped the ball in explaining how to use this one. I'd point out that sometimes you want to align your roll axis first, if your vessel isn't symmetric around it. I'm thinking particularly of BobCat's Buran shuttle, which has a docking port inside the cargo bay facing upward (like the U.S. STS's Orbiter Docking System). When you roll around that docking port, the yaw changes too, because the shuttle isn't symmetric around the roll axis. What I actually find is most helpful is to do a very rough eyeball alignment with the docking port, then use the DPAI to fine tune the rotational alignment. I've successfully docked Buran quickly and easily many times using this plugin.

Orbit-normal docking port orientation does still have the major advantage that the docking port won't rotate in yaw and pitch due to the vessel's rotation around Kerbin. However, I find that I can dock fast enough with the DPAI that it really makes no difference.

[HeadHunter67]

Indeed - that's the ideal orientation for the most efficient and fastest docking, but I agree - now I can use the DPAI to dock without worrying about the small amounts of relative rotation... because essentially, that too is just velocity that I'm cancelling that out during translation.

Three weeks ago, I could barely dock unassisted. Now I am assembling space stations as easily as a kid might play with Lego blocks. This plugin makes it go a lot smoother.

Edited September 1, 2013 by HeadHunter67

[RoboRay]

I thought that's how everyone docked. But yes, that is a great and simple explanation of how to to use the instruments to guide your maneuvering. Note that docking with the NavBall-alone works the same way, except you don't have orientation information... Assuming you are already aligned to the target orientation (using the Normal-axis, preferably), position your yellow prograde mark in relation to the pink target marker exactly the way you are positioning it to the green crosshairs using this mod. The crosshairs in DPAI are redundant, really, but extremely useful in practice because it allows you to focus your attention on a single instrument rather than scanning back and forth across several.

[NavyFish]

The crosshairs in DPAI are redundant, really, but extremely useful in practice because it allows you to focus your attention on a single instrument rather than scanning back and forth across several.

Yep, exactly. Hence why version 1.0 only displayed the alignment circle (and hence the name of the mod ) - this was the only information that could not be gleaned from the Nav Ball.

I'm starting to build a feature/change list for 3.0, though there may be a point release before then. So far:

Small stuff:

-Changes to the roll degrees (0-359.0, vice -180 to 180).

-Possibly reducing the range of the alignment and velocity vector, to improve resolution without having to resort to exponential (can't add much more before it becomes 'twitchy').

-A touch more expo on the CDI needles

Bigger stuff:

-Ability to resize gauge (it's already in there, I just need to convert to Bitmap fonts so that those will scale correctly, which is not trivial).

-Ability to cycle between target ships and target docking ports through the gauge itself (and hopefully remove the 200m restriction)

-This will necessitate have the gauge visible even when no target is selected, so I'll need to make a 'minimized' version that still allows you to cycle targets/ports.

-Since the selected port itself isn't highlighted, I may need to draw some kind of overlay on-screen (i.e. in the 'world' itself) that highlights the selected port. This might be too intrusive, though. Thoughts?

I'm also looking for inputs on the orange "fly-to" arrow for the alignment indicator. Should this be replaced with a 'retrograde' alignment indicator (might be confusing)? I think it's a bit ugly, frankly. Any ideas would be appreciated.

Please post any other suggestions you'd like to see implemented.

-Navy

Edited September 1, 2013 by NavyFish

[Mr Shifty]

Bigger stuff:

-Ability to resize gauge (it's already in there, I just need to convert to Bitmap fonts so that those will scale correctly, which is not trivial).

-Ability to cycle between target ships and target docking ports through the gauge itself (and hopefully remove the 200m restriction)

-This will necessitate have the gauge visible even when no target is selected, so I'll need to make a 'minimized' version that still allows you to cycle targets/ports.

-Since the selected port itself isn't highlighted, I may need to draw some kind of overlay on-screen (i.e. in the 'world' itself) that highlights the selected port. This might be too intrusive, though. Thoughts?

These all sound great! The HUD idea has me pretty excited. Would be great to see an approach corridor, though I'm not sure how feasible that would be.

[jrandom]

Just make the HUD toggleable! When it doubt, give the player control over it.

[NavyFish]

Quick update: Port cycling works! In my dev build, you can now press a button to cycle through all ports on the targeted ship.

I still need to come up with a good UI to indicate which port is targeted. To test the "approach corridor" concept, I'm drawing a long orange line out from the targeted port (in 3-D space), but I'm not sure how I feel about the aesthetic of a 3-d overlay. It seems a bit too 'futuristic', as odd as that sounds. Another possible approach would be to draw a 2-D circle around the target port, in "GUI' space. Thoughts?

Edited September 1, 2013 by NavyFish

[RoboRay]

I honestly don't think I would use any of the HUD "guidance" features (the beauty of the DPAI is it's already got everything without any need to look around at other stuff), but if port selection is allowed through the gauge there certainly is a need to indicate which one you've selected. Is it possible to activate the green "highlight" that appears when you mouse over parts on the view screen? That's subtle, but should be effective.

[Specialist290]

I like RoboRay's idea. Another one that might work is a simple, single-ring "open crosshairs" type of display that's minimally intrusive. Sort of like the HUD in this image (EDIT: or this one, which I think illustrates it slightly better), only it doesn't have to be nearly as elaborate.

EDIT: Another idea: What about overlaying a semi-transparent version of the orange target marker that's in the DPAI window over the target port? At the very least, you wouldn't have to use resources rendering a completely new object, and the viewer can more easily associate "This is where I need to be" and "This is where I need the ship to point to get there" if the markers are the same.

Edited September 1, 2013 by Specialist290

[NavyFish]

Is it possible to activate the green "highlight" that appears when you mouse over parts on the view screen?

Indeed, that works nicely. I've tweaked the highlight to 'pulse' around a 1-second period, which helps bring the eye to the port. I'll put in a toggle to enable/disable highlighting.

This works at close range, within 50 meters or so. Outside of that, it's pretty hard to see the highlight, but I think I have a solution that keeps with the simplicity/subtlety of this one. Stay tuned.

[Rybec]

You might consider looking at the Dock MFD that comes with Orbiter for ideas, although at this point you've already implemented most of it. It shows which port is selected by drawing an approach corridor on the HUD: The extra line indicates the "top" of the docking port; in this shot the ship needs to roll 180 for proper alignment You might also consider limiting the choice of docking ports to ones that match the size of the one you're controlling the ship from. So if you're trying to dock with a jr port you can only cycle through the target ship's jr ports.

Edited September 1, 2013 by Rybec