Author Topic: Feature Request - Custom Pushback Guideline  (Read 1850 times)

downscc

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Feature Request - Custom Pushback Guideline
« on: July 03, 2019, 06:38:41 pm »
I notice that when setting up the pushback stop location in Snap mode that you provide dashed lines to visualize the pushback path; however, in Free mode no such visualization help is provided.  We see the spline spot and that's it.

I assume the spline spot is a Bezier point providing a constraint to the solution of the Bezier polynomial curve but in playing with the location of this point in a dozen different cases I have run into some surprise results.  For example, I've run into cases where the push back starts as a sharp turn directly  from the start/park point and then does a loop before continuing onto the expected path.  I suspect this is something I'd see immediately if there were a dashed line indicating the path of the Bezier curve during the visualization setup procedure.

Please add dashed line visualization to the Free mode as already is provided for Snap mode parking customization.

virtuali

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Re: Feature Request - Custom Pushback Guideline
« Reply #1 on: July 03, 2019, 06:48:07 pm »
Quote
Please add dashed line visualization to the Free mode as already is provided for Snap mode parking customization.

This won't do much, because the actual spline will change depending on the tow truck you *will* use in actual flight, because it's not a simple polynominal Bezier spline, but it takes into account the mechanics of the whole system, which is the tow truck wheelbase + the eventual towbar length + the distance from the front gear to the airplane pivot point.

The only way to do it accurately, would be running some sort of simulation, and possibly asking you which airplane+vehicle pair to use but at that point.

downscc

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Re: Feature Request - Custom Pushback Guideline
« Reply #2 on: July 04, 2019, 09:05:22 pm »
Thanks for the reply; however, I respectfully ask that you reconsider.  I've noticed during multiple pushback trials that the aircraft center point, marked with a red X in your visualization, does seem to follow a curve as I imagined it would appear if you added the dashed lines.  Of course, the nose gear and tug follow a much different path that depends as you say on the mechanics of the scenario but I'm not asking for that to be displayed. 

Also note that the dashed lines displayed in the Snap mode simply follow the underlying AF file links, and the actual aircraft movement will vary as necessary especially with acute angles. 

Finally, I'd like to thank you for adding this pushback feature.  I've revised or updated parking customization for a half dozen FSDT airports so far and the Free mode comes in really handy in a couple of cases at each location.

virtuali

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Re: Feature Request - Custom Pushback Guideline
« Reply #3 on: July 05, 2019, 04:15:29 pm »
Of course, the nose gear and tug follow a much different path that depends as you say on the mechanics of the scenario but I'm not asking for that to be displayed. 

But since we already planned to do a "proper" simulation, it wouldn't be very smart spending our development time to draw a rough preview curve, only to have it eventually replaced with a proper simulation. Better doing it right first.