rock1 Posted July 9, 2014 Share Posted July 9, 2014 How can I draw lines which are tangential to an spline or an arc? I drew this manually just like that by intuition... Quote Link to comment Share on other sites More sharing options...
eldon Posted July 9, 2014 Share Posted July 9, 2014 Have you tried to use the Tangent Osnap? Quote Link to comment Share on other sites More sharing options...
rock1 Posted July 9, 2014 Author Share Posted July 9, 2014 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 Quote Link to comment Share on other sites More sharing options...
steven-g Posted July 9, 2014 Share Posted July 9, 2014 Try a block (line) with an alignment parameter. Then explode the block SplineTan.dwg Quote Link to comment Share on other sites More sharing options...
rock1 Posted July 9, 2014 Author Share Posted July 9, 2014 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. Quote Link to comment Share on other sites More sharing options...
steven-g Posted July 9, 2014 Share Posted July 9, 2014 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. Quote Link to comment Share on other sites More sharing options...
rock1 Posted July 9, 2014 Author Share Posted July 9, 2014 (edited) 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 Edited July 9, 2014 by rock1 photo upload Quote Link to comment Share on other sites More sharing options...
steven-g Posted July 9, 2014 Share Posted July 9, 2014 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 Quote Link to comment Share on other sites More sharing options...
scj Posted July 9, 2014 Share Posted July 9, 2014 You can make a short Lisp, using vlax-curve-getFirstDeriv Good luck Jochen Quote Link to comment Share on other sites More sharing options...
rock1 Posted July 10, 2014 Author Share Posted July 10, 2014 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. Quote Link to comment Share on other sites More sharing options...
scj Posted July 10, 2014 Share Posted July 10, 2014 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 Quote Link to comment Share on other sites More sharing options...
rkent Posted July 10, 2014 Share Posted July 10, 2014 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 Quote Link to comment Share on other sites More sharing options...
steven-g Posted July 10, 2014 Share Posted July 10, 2014 I'm glad somebody liked it, thank you Quote Link to comment Share on other sites More sharing options...
rock1 Posted July 18, 2014 Author Share Posted July 18, 2014 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 Quote Link to comment Share on other sites More sharing options...
Dadgad Posted July 18, 2014 Share Posted July 18, 2014 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! Quote Link to comment Share on other sites More sharing options...
jarr3tt88 Posted July 25, 2014 Share Posted July 25, 2014 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! Quote Link to comment Share on other sites More sharing options...
ivanchica Posted May 17, 2016 Share Posted May 17, 2016 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? Quote Link to comment Share on other sites More sharing options...
rkent Posted May 17, 2016 Share Posted May 17, 2016 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. Quote Link to comment Share on other sites More sharing options...
ivanchica Posted May 19, 2016 Share Posted May 19, 2016 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? Quote Link to comment Share on other sites More sharing options...
guran Posted May 19, 2016 Share Posted May 19, 2016 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. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.