Hello everyone,
What explain or can explain that my surface appears much longer than expected once flowed along !?
The base and the semi-circular surfaces are the same dimension before rounding the second one. I just mean that they are consistent, not exactly the same. Quite more exactly the same in the other direction.
Is that enough to explain the issue ?
not quite. and upload a model or sample please. 
developpe.3dm (179.5 KB)
Sure !
Hi @bertrand.audinet
Use ShrinkTrimmedSrf your semi-circular surface (Turn on control points to see the full, original tubular surface “info”). Currently it’s a trimmed surface, and FlowAlongSrf will use the untrimmed version.
Very nice and easy 
I must learn because it comes from a “polyline” (i come from Autocad, when i speak 
) that i extruded.
A “limited” object is not common for me.
Hi @bertrand.audinet
I actually wondered that myself. If the underlying curve was always half a circle - if you extruded the original curve, that is - I’m a bit puzzled as to why the surface is trimmed. From the looks if it, you must have made a cylinder (either using the Cylinder command or by extruding a circle) and then trimmed off half of it?
-Jakob
Thanks for this part. It’s done.
I beleive it is a good idea to continue here… the file is the same.
What about this phenomenon ? It goes in the wrong direction… How to simply reverse one of the starting or target surface ?
Another topic would be : how to do it in one manouver ?
If I ShrinkTrimmedSrf the three starting target surfaces, it doesn’t allow me to mergesrf without deformation…
Oh ! And thanks for this simultaneous answer too
To be more understandable on my last question.
How to make 3 in 1 as a target surface ?
Note how the command prompt asks you to pick an edge near matching corner of the target surface? That’s in order to get the orientation right and sometimes it’s a little… fickle. But it gets better if you use a single surface instead of many small ones, so on to the next question…
I’ve taken the liberty of cleaning out your file, so now it’s just the geometry used in the video. Also rotated the originals upright so that the orientation is a bit closer to the intended, final result - just to make it a bit easier to see what’s going on. For this operation you only need:
Your original surfaces
A baseplane (a single flat surface, coincident with the original surfaces)
A single, untrimmed target surface.
The untrimmed target surface is achieved by extruding your original curve with the switch SplitAtTangents=No as seen in the beginning of the video. And notice how I pick both the base surface and target surface in the same, lower corner when flowing the surfaces.
HTH, Jakob
I did it again, from the top but, guess what : I am under release 7 too but no SplitAtTangents option…
And it doesn’t work…
In your file, it is a surface, in mine, an open extrusion…
Hi Bertrand -
Run the UseExtrusions command and switch to Polysurface. Then run ExtrudeCrv again.
-wim
Got it.
I remember that I ever read about that.
And now : I know what it means, at least 
Will give it a try soon.
Many thanks.
