How to import CATIA file to MATLAB for analysis of curvature radius?

[Sacaq]

Hi~
I am using CATIA V5R21.
I am trying to analyze the curvature and curvature radius of a surface in CATIA.
However I found I can't export the curvature along any curve or on a certain point along a certain diraction on the surface.
I thought maybe it is possible to export the surface to MATLAB and then get the coordinates of points on the surface to calculate the curvature and curvature radius.
Could anyone kindly help?
Thank you!

 

[itsmyjob]

what's wrong with the curve or surface curvature analysis in CATIA ?

I've been able to get all I need with any surface so far...

Eric N.
indocti discant et ament meminisse periti ​

 

[Sacaq]

The curvature or curvature radius of any point on a surface can be shown in CATIA using "On the fly" in "Surface Curvature Analysis," and
I can't executed this function on a certain position.
What I can do is to move my pointer and see the value on the CATIA window, but this would not show a accurate curvature or curvature radius value on a certain point I wanted.
When the "Porcupine Curvature Analysis" was applied, a smooth curve of curvature caould be found in the "2D Diagram."
However , I don't know how to export these curvature analysis result.
As a result, this is why I would like to export the result or export the equation of the surface to MATLAB to calculate the surface curvature or something else.

 

[LWolf]

one can also construct/assign a curvature value to a point using Measures/Curvature from formula editor. curvature(crv:Curve, ptoint):Real

regards,
LWolf

 

[Sacaq]

I added a formula on a point in Formula Editor as attached picture, but I can't require the curvature value.
Would you please kindly tell me how to do? Thank you!

 

[itsmyjob]

could not get your picture.

problem is a bit more difficult to get surface curvature on 1 point. The curvature is define by the minimum curvature and the maximum curvature, so we have to find those 2 directions first then do the math.

if you have few point, you could consider using CATIA, for large number of point I would check at my options.

Steps to get the Gaussian at 1 point:

on 1 point create 1 plane tgt, then a circle on this plane. using the one inertia axis of the circle as ref direction, I would create an angle line to this ref direction. I would then project (along direction normal to the plane) this line on the surface and check the curvature at the point. Then I would change the angle from 0 to 90deg with a step accurate enough for my computation. I would check all curvature. if the minimum is at 0 and the max at 90 then I'm really lucky. In most case I would get either the minimum curvature direction or the maximum direction. From one I would get the other direction (they are 90deg from each other).

With the 2 main curvature directions I would just multiply the minimum curvature with the maximum curvature to get the Gaussian value.

I just made a powercopy of this, and playing with the angle I find the proper value within 1 minute for each point.

Eric N.
indocti discant et ament meminisse periti ​

 

[LWolf]

create a parameter, type real.
add a formula, go for Measures, double klick on the curvature(crv:Curve, ptoint):Real
you need to have the curve ready, as well as the point. As ItsmyJob says, this function is for wireframes(curves) and not surfaces...

regards,
LWolf