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Arc helpers

Don I am not sure what the bezier function in GMax does - how do you define the shapes?
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It's not a Bezier function per se (even though I've been referring to it as such). Basically, you draw a line between the two end-points and add new points along the line which become Bezier handles which can be moved. The shortcoming is that you must then create an object (I used a three-sided, multi segment cylinder and later deleted two sides) and place it's vertices along the line - extruding the cylinder as many times a necessary to generate the required number of sections.

I've never used an arc helper shape, but I gather you specify the arc dimensions and the number of vertices it is to contain - which then becomes a line of that shape. The difficulty I see is that the resulting lines must then be manually placed end to end to create complex shapes. (This is what I was referring to by "hardly ideal") George indicates it took him about 30 minutes to complete that one pattern. That's comparable with the time it would take to do it "the Gmax way" - including trial and error locating.

If ADE were to offer a capability similar to what I have described above, even if you had to manually fit GP line segment vertices along the "Bezier" line, that time would be reduced to a few minutes. If that line were to be a true helper, placing a user-specified number of vertices within each segment (the same number for all segments), that would reduce the time even further since the user would then only have to delete vertices along straight line portions or, perhaps, add a few more on long curves for smoothing.

What I like about the GP lines is that they "merge" when they become tangential
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That's because the backing is drawn one layer lower than the line itself - an entirely unintended feature.

Don
 
Lot of ideas here - something for me to think about while the lawyers play ;)
 
One other thought which applies to the "Bezier helper" as well as being a potential solution for an issue George highlighted a couple of days ago regarding specifying the number of vertices in an arc helper.

Instead of specifying # of vertices, why not specify the maximum angle of change in any segment beyond which a vertex would automatically be inserted. Such a specification - which is a measure of rendered curve quality - would apply to any arc, regardless of angular length or major axis.

Don
 
Jon (for obvious reasons) we haven't heard from you for a while on the topic of a Bezier Helper, i.e., a series of connected, but individually editable, arcs and lines.

A thought has just occurred to me. In George's example below, the major difficulty I see is that the individual elements must always be handled individually.

If you are not well-along with the implementation of a true Bezier helper, a "poor man's substitute" might be simply the ability to connect lines end-to-end and, thereafter, be handled as a single object.

Don
 
I think my last comment on the subject was to ask if this is still a requirement given that in practice Bezier curves will not be used in the real world but rather arcs. I do not recall getting any comments that Beziers are still required.

To be clear a Bezier is defined by some points in space. However to be of any use it is then converted into a series of vertices that represent that curve. Perhaps I am missing the point here but what is the benefit of providing a bezier over an arc?
 
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From my perspective, it's not the nature of the curve that's critical, it's the ability to link those curves/arcs with straight line segments and other curves/arcs, the whole constituting what I'll term "a complex line". A simple arc (as an element) is probably adequate.

Don
 
Yup, I still miss the "Bézier" shape for the reasons Don managed to put into words better than I could.
Like when I would want to draw this red taxiline:


jvqh.jpg
 
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Jon, just brain-storming.

Another way that should give us the basic capability I'd like to see would be allow the user to select two vertices in an existing line and then have the arc helper shape "do it's thing" between the two vertices - using them as the endpoints.

This would, for example, allow you to select the endpoints for a curved segment of a line and have the helper shape fill-in the intermediate points. You might even be able to require that the two vertices be preceded/followed by a straight segment and use the intersection of their radials to preset the (maximum) radius, leaving the user to specify only the number of points -perhaps by subtended angle.

Don
 
I don't see why having one curve is better (easier to manipulate) than multiple curves.

This small airfield has over 130 lines.



At compile time, each curve will be broken down into segments and triangulated, won't they?
 
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I don't see why having one curve is better (easier to manipulate) than multiple curves.
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It's not one curve, George, it's one line potentially containing more than one curve with, perhaps, intervening straight sections.

Obviously, the straight and curved segments can be created and handled individually. (I presume that's what you are doing.) But, doing it collectively as a "complex line" avoids any discontinuity where one segment joins another - which must be very exact when handled individually. And, if the line or a portion of it has to be moved, doing it as a single line is - to me, at least - more convenient.

What I am proposing could be viewed as a parallel to the creation of a multi-segment taxiway where you also get to specify the rate of curvature. In fact, if Jon were to find a way for ADE to calculate the needed curvature to join two straight line sections (a la taxiways), there would be no need for a helper. (You'd specify rate of curvature on a per project basis.) If that were possible, an alternative would be to let the GP editor do it instead - but doing it in ADE allows the result to be previewed prior to compilation.

Incidentally, I've never found the need to use GP lines as taxiway centerlines or other "standard" markings as you seem to be suggesting in the 130 line example. To me, it's more convenient to use custom configurations of taxiway and apron links/nodes. My primary need for "complex" GP lines is for parking lead-in/out lines (which often are different from taxi/apron link centerlines), apron boundary lines, line configurations that require sharp corners, etc. To each his own.

I suspect, for you, it's a case of you don't miss what you've never had/used. In my own case, I could and often did create "complex" lines in Gmax - albeit in a non-intuitive manner - using a Bezier function - and I found it very convenient. I believe ADE_GP would be a better "product" if it had similar capability.

Don
 
Folks

For the avoidance of double I have no problems creating Beziers in ADE - it already uses them to draw all the taxiway markings.

My original question was why? The answer is given - to be able to draw complext curves.

PS - can I suggest we stop talking about Beziers and start talking about complex curves please?
 
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