Sharper corners in MPCC

[Joe Horn]

As you know, the MPCC code generates spline curves between waypoints, with the result that flying through the four corners of a square will round the corners (like a baseball player running the bases) like this:

At the risk of stating the obvious, the sharpness of corners can be adjusted by simply placing additional waypoints strategically along the intended path, like this:

Disclaimer: This forces Solo to slow down at the corners, so it's a tradeoff between how smooth you want the video to look (which is MPCC's main claim to fame) and how sharp you need the corners to be.

One very practical application for this technique is crash avoidance during vertical turns. For example, if you set MPCC to fly through two low-altitude points immediately after a higher-altitude point, the resulting spline might actually run into the ground without warning. The above technique can be used to force Solo to fly a straight line between the two low-altitude points.

 

[erikgraham]

One very practical application for this technique is crash avoidance during vertical turns. For example, if you set MPCC to fly through two low-altitude points immediately after a higher-altitude point, the resulting spline might actually run into the ground without warning. The above technique can be used to force Solo to fly a straight line between the two low-altitude points.

Great tip.

 

[pyrate]

It works, this was noted on FB after someone did a vertical L turn and had solo fly into the ground.
the trick is not putting them too close together, it will literally freeze if they are too close together

 

[RichWest]

Nice work around... I did a tight orbit with MPCC and it performed extremely well, had 9 WP to make the complete 30' circle.

 

[pyrate]

here is the graph we used, showing how to add a fourth point to a vertical drop to arrest descent and prevent flying into the ground

 

[RichWest]

That's another great tip @pyrate. I never would have thought about that, until I'd plowed the ground or trimmed a tree...

 

[pyrate]

it dawned on me when Nick was explaining how the turns were calculated in MPCC. They are not true Bezier. so I googled the curve algorithm he mentioned. It came back with heavy references to computer graphics, 3D modeling.
In those disciplines you smoot a surface with a subsurface mesh. it basically smooths everything. To sharpen and edge you put two lines very close together, limiting the curve.

turns out to work great

 

[giorgos.kokkas]

Microsoft Visual Basic and Plc logo Siemens


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[RichWest]

Practicing some mpcc this weekend, seems like a good time to bring this thread back to the top for others.

I was looking for a video showing a mpcc flying around a barn from someone here...It was a great demonstration of mpcc in action. Wish I could find it...

 

[Jubalr]

Practicing some mpcc this weekend, seems like a good time to bring this thread back to the top for others.

I was looking for a video showing a mpcc flying around a barn from someone here...It was a great demonstration of mpcc in action. Wish I could find it...

Remember this one Rich? It was a great example of what MPCC could do with a single operator filming himself. This guy would set the shot up, then hit start and set the controller down and run a trail.

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[RichWest]

Yep, actually amazing work on several levels.

 

[Greg Parker]

Rich here you go:

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[RichWest]

Rich here you go

Winner-winner, chicken dinner...that's the one.

 

[xlntpix]

This thread is ancient, but I had to give it a look. Just got into flying the Solo because of its "MPCC" function. In motion picture Visual Effects we have various Motion Control camera systems that use a variety of spline curves (bezier, j-spline, conic, etc) to create our camera moves via endless keyframes (read here: waypoints). The one trick we have, because it is software (not cpu) is editing the move through graphic move editors (similar to autocad, graph editing in Maya, AfterEffects, etc). Except in Motion Control we would "trick" the moves by adding, slipping or "pinning" additional keyframes, not unlike some of the suggestions here. One of the consequences in all of this "math vs. the real world" is that when you pin too many points close to each other to trick the curve, motors stall, cameras crash, people cry, and this case, drones plow into the ground. I always like to think of a rubber band that you stretch around several pivots.