Topic: Triangulation (re-visited)

[pedroantonio]

hI sanju2323. nice lisp for Profile. Do you have any lisp for crossections ?

[pedroantonio]

somethin like this

[AARYAN]

Hello ymg,

I have used your routine and found the results are very good.
But unfortunately it takes a long time of approx 90 secs to process 13000 points. If I remove the getneighbour function it reduces the process time but I doubt if I miss some important sort of things by removing this function. So I would request to please tell me what does this function do in the routine? Is it safe I remove it out or shall I wait for another version which may increase the speed.

Thanks for your help.

[ymg]

AARYAN,

You are pushing the enveloppe with a 130000 pts.

The function get_neighbour establish an array of pointers
to each neigbouring triangle.

It is used for profiling and voronoi.

If all you need is the triangulation, you could
do it without generating it.

ymg

[AARYAN]

ymg,

Thanks for your reply. BTW there are only 12628 points and the elapsed time is 82.7120 secs; 25156 3DFACES, but if I remove the function get _ neighbour the elapsed tine reduced to 30.5760 secs, 25156 3DFACES.

Regards

[sanju2323]

Try this lisp

[ymg]

sanju2323, AARYAN,

Thanks for your upload of these profiling apps.

However, it is not a good idea to profile from contour
if you have a TIN. 

It does come handy if all you have are contour digitized
from a topographic maps.

I do have a way (unpublished yet) to do it without going
through get_neighbour.

Question: Which version are you using ?
                It should not be that slow with only 14000 pts.

ymg
               

[AARYAN]

Hello ymg

I am using Triangulation vs 0.5.9. Am I not using the latest one??
Please provide routine which is faster as you said if possible. BTW I am looking for triangulation lisp.

Thanks for your help.

[ymg]

AARYAN,

If you are not doing profile, simply remove
the (setq nl (get_neighbour tl)) at the end
of the triangulate routine.

I am at version 0.6.0, but not ready to publish.
Slow progress because I am traveling a lot
these days.

Other option to accelerate would be to compile
it into a vlx.

ymg

[AARYAN]

Thank you ymg, I am actually doing the same i.e removed the last line of get_neighbour function but not compiled the routine yet. I will do and post the result.

BTW most of the structure of Triangulation function is similar to Mr.Elpanov's routine then what makes it run slower?? Cant we modify the those portion to achieve the speed if possible?

Regards

[ymg]

AARYAN,

The triangulation portion is Evgenyi's code.

Only diffference is that there is code to remove possible duplicates and a section
to generate Voronoi's diagram.  There is also a section for breaklines.

So if you have no breaklines and are not generating Voronoi the speed
penalty is only the check for duplicates point.

ymg

[AARYAN]

Thank you for your quick reply and Yes I do not want to generate voronoi diagram but sometimes I may have breaklines. It would be great If you can edit the code to force the algorithm work only for Triangulation then I think i may get what I need.

I must say your contour routine is truly amazing and highly appreciable.

Regards

[pedroantonio]

Hi sanju2323 i know quick profile lisp but is not what i am looking for.
I  want a lisp for cross section like the upload photo (with center Alignmet)

[sanju2323]

Topographer,
Complete Solution In This Program Please try to Cadtools Program http://www.glamsen.se/CadTools.htm

[sanju2323]

ymg,
 You can generate profiles from 3d polyline? If you have any lisp.