Programming mutliple curve, island etc

[kidznok]

Hi,
I would like to start studing autolisp.
I would like to know how hard is creating app like that:
https://www.youtube.com/watch?v=_JUUNztr7rk
to draw multiple curve, island etc.

[ВeekeeCZ]

The user interface is quite simple.

The real deal is all the math behind it. Are you good at geometry? You don't need to know LISP to do the math. Excel is just enough to start.

You have given 3 points (their x,y coords) and five radiuses. Now calculate arc center points, start and end points. For all of them. 

[-didier-]

Bonjour @kidznok 

"I would like to start studying autolisp."

Very good ! Welcome to a wonderful world.

Can I give you some advice?

I think that to "start" the goal is a bit complicated.

When you learn to walk, you don’t start with an obstacle course.

I think you have to start by understanding the language,
learn a few functions, and then gradually level up.

Amicalement

[Sea-Haven]

Having drawn traffic islands from scratch they are complicated, working with geometry of curves will take some understanding, cheating a bit using CAD is much easier and taking advantage of fillet, TTR etc in sequence, possibly taking all the steps and rolling into a lisp. A manual/auto approach. When you get into islands that are curved on entry to another road you draw it and then find the vehicle check runs over the kerb. So may not be a draw once.

Did you contact the Youtube provider ? Or is it a case of I don't want to pay. 

[john.uhden]

@kidznok and @Sea-Haven ,

@Sea-Haven is dead on correct.  Way back in the day I designed highway geometry with a crank calculator (no memory) and books of sines, cosines, square roots, etc.  First I would draft the design with a scale, beam compass and my favorite, the Civil Engineer's Radius Guide.  I developed the axiom "if you can draw it, you can calculate it."   Of course I used up every English and Greek character with reams of computations.  Then AutoCAD 2.67 (whatever) came along and I found that if I could draw it, it was calculated.

That's where you have to start... drawing the design in AutoCAD using the extensive arsenal of AutoCAD commands.  Then, if you can describe what you did and find AutoLisp functions that can do some of it for you, you will eventually be able to "speak" and write AutoLisp.  A lot of what you would like to be able to do will be beyond possibility in the beginning, but only because of lack of knowledge and experience.  But if you keep asking salient questions, the helpful brainiacs around this place will guide you toward your solutions.

I hope to hear more from you.

[Sea-Haven]

Thanks John

"Then AutoCAD 2.67 (whatever) came along", for me 1.4.

Kidznok so have a go start with circle and arcs, use the CIRCLE TTR command a lot as this will do correct radius curve between 2 arcs, fillet will fail most times. Like John think about what steps are repeated.

Took like 2 minutes

Another hint, Line tan pickcircleedge tan pickothercircleedge do other side. Do trim the circles out, then pedit, join and offset for kerb.