Video tutorial: Making sense of curvature

[solidworm]

Hi everyone,

I made a video tutorial titled "Making sense of curvature
in creo", i discuss how to draw an osculating circle to
get a visual feel of the curvature and compare the
results
with ProE's curvature analysis feature.

In case you found it useful, please consider adding
a good rating or a like, as this is a competition for a kindle fire.

Here's the link:

http://communities.ptc.com/videos/2668





Edited by: solidworm

 

[sohailabbas]

Very nice effort

 

[solidworm]

Glad you liked the video, anyone found the video
interesting?

 

[DonChunior]

Hi solidworm,


nice video!
I like it too!

 

[dgs]

Nice video, quite helpful. I never understood that
curvature is simply 1 / radius at any given point.

BTW - You can eliminate your double regen by putting your
relations to calculate the double relation by placing the
relation driving the 'circle_crvt' parameter in the 'Post
Regeneration' section of the relations dialog.

 

[solidworm]

Thanks Doug,glad to hear it was helpful. Thanks for your
tip!

 

[design-engine]

curvature (continuity) and tangency are both a relationship between two curves. I did not listen to the sound but It looks what they are describing is rate of change or acceleration of a curve... ie the radius of a curve at a point.

The spline he drew is a 3 degree curve two spans. Also a mistake in an effort to describe curvature.


Edited by: design-engine

 

[solidworm]

Bart, I think you have misunderstood something here. curvature is exactly 1/Radius and it could be measured at any arbitrary point of any curve, be it a line, a circle or a spline or any other type. I'm not discussing curvature continuity in that video, which you are talking about. curvature continuity is the case where curvature value (which is discussed in the video) of the two joining curves are equal at their joining point.
BTW, i'm not seeing your "like" bellow the video, go ahead and "like" the video.

Edited by: solidworm

 

[tobbo]

Nice Video , you got a "like " from me.

 

[solidworm]

Thanks Tobias.Glad you liked the video.
Only Tobias voted for(liked)the video from this forum.
seems like either i'm not good at making tutorials or i
was totally wrong as Bart suggests.

Disappointing.I promise i'll never make a video again.

 

[dgs]

I thought I had, I just went and corrected my oversight.

 

[tobbo]

http://www.youtube.com/watch?v=T143lv8aKDU


@Bart - please elaboroate why a 3deg, 2 span curve would be a mistake when describing the value for curvature in a certain point? If you discuss curvature continuity thenI can see your point, but i cant see how the curveitself would affect a point on a curve regarding the value of the curvature?


//Tobias

 

[solidworm]

nice video Tobias, the circle he shows in the beggining of that video is the osculating circle that i draw in my video. it works for 3d curves as well. the formula i used to calculate the curvature is Equation number 4 here:

http://mathworld.wolfram.com/OsculatingCircle.html
ofcourse its more accurate to use formulas used in that video, but we don't have any equations for curves generated in ProE models. that Equation 4, allows a graphic approach to be used with help of ProE, by selecting t1,t2,t3 as point offset ratios as seen in the video (they should be close enough), C which is the osculating circle can be drawn. then 1/R is the curvature at the desired point. (corresponding to t)




Edited by: solidworm

 

[mgnt8]

Great video Solidworm.


You should come take the advanced classat Design Engine. I'll bring some beer and we'll have a nice round table discussion on curves & surfaces. Can you file for asylum or something and head to Chicago for a week?

 

[solidworm]

Thumbs up Greg, you got a like from me, for your sense of
humor.