lisp - intersection point coordinates and distance value

[Ale3397]

hi to all, I need your help to try to automate the following procedure on autocad:
I need to know about each section of a gallery (even more than 1000) the distance between the train silhouette and the tunnel cap (dx and sx side) in order to be able to obtain this data in a table form. you allego screen:

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in both sides of intersection between the green 3d polylinea and the block of the train silhouette in red.
I ask you therefore if through the use of a lisp I can get the value of this distance either equal to 0 or different from 0, it would be perfect to read a quota in these points, then to exploit the data field to be inserted in a table and export it to excel.
if you have other tips on how to speed up work are well accepted!!! Thank you

 

[Cristallo]

never seen a gallery like that, it is out of every safety standard.
Is it not that you are doing a job to keep you busy?
1000 sections? sections every 50cm or do you have a 20km tunnel?

 

[Tristus]

Sorry, but who designed that gallery will surely have taken into account the encumbrance of the wagons and will surely have made sure that the distance between the time and the wagons respected the norms to which it referred crystal glassIt is absurd that there may be a distance or even an encumbrance of the wagons that could exceed. That sounds weird.
or the design of the gallery section is out of scale or the design of the wagons is out of scale.
otherwise it is necessary to re-excavate the gallery.

 

[Gio_S]

but it will be an exercise, in railway there is a concept of limit silhouette to be respected that has not at all those proportions and does not depend on the inclinations of the rotabili, and varies from country to country. When does a tunnel tilt with the train? but if it is an academic exercise to solve it is very complicated, each curve produces a different inclination, but how is it defined? In theory I think we should create two complex solids, external gallery volume and three-dimensional projection of the passage of trains, all first straight and then passing to a curvature with an increasingly narrow radius. and then you can study the algorithm to locate, take a section that matches the desired radius, if and where there is the going between the two volumes. As certain rendering programs do, which obviously must represent the intersections and volumes, they pass them to hits of Boolean operators. But it's not a joke at all.

 

[Cristallo]

Actually knowing how to use autocad, the question is simple relative:
polylinea 3d of the gallery trend, on which to "sweep" the section and to obtain the light of the gallery.
polylinea 3d plane run, on which to sweep the train silhouette, and get the train encumbrance along the run.
you will remove from the lumen the train encumbrance and you will have a solid that represents the franc between railway silhouettes and tunnel lumen in every point.
but from here to chart these values passes...

 

[Gio_S]

if the volumes of the train and the gallery are perpendicular to the sure plan that yes, but in this problem the curved train chart on parabolic (as to the real, in fact) and also the gallery(!!). Moreover the shape of the train cannot be constant, each carriage becomes a rope of the arc of the curve. In short, both the question is a bit rudimentary and imaginative. so I would say that applying above does not suit in the absence of other better defined info.

 

[Tristus]

It's not easy. the program should take into account the 4 superior coordinates relative to the edges of the car. to each control section a comparison with the coordinates of the gallery at that point.
mathematically it is feasible, but it is necessary to provide also the radius of the curves, in addition to the length of the wagon and its height from the track. I think it is necessary to provide the coordinates of the point where the wheels rest on the tracks.
at that point you begin to check the first curve giving the program as input the radius of the curve, the number of the control sections and the coordinates mentioned above. a challenging job, if you want to do the job mathematically.
it would take a dedicated program

graphically it is definitely less expensive, as described by crystal glass