draw lines which are tangential to a spline?

How can I draw lines which are tangential to an spline or an arc?

I drew this manually just like that by intuition...

Have you tried to use the Tangent Osnap?

Have you tried to use the Tangent Osnap?

Yes, but that's for when I choose a point [say point Max payne] anywhere and draw a line from it, OSNAP detects the tangent on the spline so that the line drawn from the max payne point is tangential, what I want is

I choose a point on the spline [that will become the tangent one] , then I make a line from that particular point

Try a block (line) with an alignment parameter. Then explode the block

SplineTan.dwg

Try a block (line) with an alignment parameter. Then explode the block

How did you do this? I downloaded the file, you've made the straight line a block. Then? I didn't understand what exactly are you doing.

There must be a straight off method for this. some right clicking or pressing some key, I'm having a gut feeling.

Just a line, that is made into a block, then an alignment parameter placed at the centre of the line, thats it, the only alignment you can have on a curve is the tangent.

How are you using the align thing? I never use the align command. I use the rotate command then press R to align my objects. Can you post step by step screenshots?

I used to work in an office where a guy told me to shift+right click on the spline and you can draw any where a perpendicular to it then a tangent, something like that.

I drew a lot of RAYS form this command some years back..can't figure out

No commands, insert the block and drag it by the align grip (center of line) onto your spline it will align itself as you drag it around the spline

You can make a short Lisp, using

vlax-curve-getFirstDeriv

Good luck

Jochen

You can make a short Lisp, using

vlax-curve-getFirstDeriv

Good luck

Jochen

What is this? I'm an architect and don't know any computer language. Kindly provide the file.

Hi rock1,

attached is a LISP.

Load it and start it by typing "ablpkt_vlax" at the command line.

Then use OSNAP (for instance "Next" to define the point at the spline) and give a length for the tangent to draw.

Good luck

Regards

Jochen

ablpkt_vlax.lsp

Just a line, that is made into a block, then an alignment parameter placed at the centre of the line, thats it, the only alignment you can have on a curve is the tangent.

Excellent solution, very clever. +1

Hi rock1,

attached is a LISP.

Load it and start it by typing "ablpkt_vlax" at the command line.

Then use OSNAP (for instance "Next" to define the point at the spline) and give a length for the tangent to draw.

Good luck

Regards

Jochen

It is not working. I tried.

When I use the specified command, I get a square box to select my object. I select my spline. Then it asks me to enter my length of tangent, I enter say 9000, then bang, I get ; error: bad argument type: numberp: nil

This is a copy paste from the list window

Command: ABLPKT_VLAX

Pick the graph of a function at the ablpoint (use osnap!):

Select object:

Length of the tangent :9000

; error: bad argument type: numberp: nil

I'm glad somebody liked it, thank you

I missed this earlier, just saw it, as usual steven-g has a real knack for thinking outside of the boxes!

Just a line, that is made into a block, then an alignment parameter placed at the centre of the line, thats it, the only alignment you can have on a curve is the tangent

Excellent solution, very clever. +1

In addition, if you added a field to that tangent line block, you could also extract data from it like the radius or something!

Hi! I haven't quite got this

Just a line, that is made into a block, then an alignment parameter placed at the centre of the line, thats it, the only alignment you can have on a curve is the tangent.

I make a line into a block, and place an alignment parameter at the centre of the line. But when I drag it to the spline, it rotates, and changes its direction, it isn't parallel any more to the given line. Can you help me please?

Is there a way to find out where is the point on the spline in which line is the tangent to the spline, but so that it stays parallel to the given line?

Hi! I haven't quite got this

 

 

 

I make a line into a block, and place an alignment parameter at the centre of the line. But when I drag it to the spline, it rotates, and changes its direction, it isn't parallel any more to the given line. Can you help me please?

 

Is there a way to find out where is the point on the spline in which line is the tangent to the spline, but so that it stays parallel to the given line?

It appears that you are asking for a second line to be added to the spline that will be parallel to an existing line and tangent to the spline at another location along the spline. Sorry I don't have a solution I just wanted to see if that is what is actually being requested. We all thought you wanted one line tangent to a spline.

Sorry, maybe I haven't explain myself good (don't speak english very well)

The red one is a given line. Is there a way draw a tangent (blue) to a spline so that tangent is parallel to a given line? I have done this manually, but I was wondering is there a way to determine where exactly is the point on the spline in which that tangent touches the spline?

You can "FATTEN" the spline and thus converted to a polyline of arcs. Then draw a line from a selected arc center perpendicular to the given line.