hello everyone,

i have an issue with the flow command. i am trying to project a surface onto a irregular tube. therefore i have unwrapped all my surface and constructed a plane that is consisted of the true length of of a number of sections, so that i can project different patterns onto the surface without distortions (screenshot 01). but moi seems to project from an imaginary rectangle and not from the corresponding lines (screenshot 00) you can even see that the outline of the unwrapped surface is not even hitting the middle line on its broadest part.

is there a possibility to solve that problem and tell moi to use the real outline of my unwrapped surface instead of an imaginary rectangle or is there a workaround for a problem like this (using the projection mode is no option as i have to project irregular patterns as well and don t want to have a crease on top of the tube and of course there would be distortion if i used projection)


thanks for any help or suggestion,

forty

Hi forty,

the shown surface seems not undevelopable?? Flow makes the the distortion of the curves by itselve. So you should try to use a rectangle face as base surface to map the lines to your revolution.
It helps to switch on the control Points of both surfaces to have a look to the parameterisation. Or You can try to rebuild the surface by sweep -> two profiles -> two rails and try again.

Kind regards
Karsten

Hey Karsten,



thanks a lot, I really appreciate it.
my mistake was indeed to have created my base surface as a planar oject. Creating it as a sweep or a loop solves the issue i was having and projects the pattern distortion-free around the tube (screenshot 02).




kind regards,
forty

Hi forty, looks like you got it all figured out! Yes like Karsten answered above it can be a good idea to look at your surfaces using Edit > Show pts to see the control point structure of the full underlying surface - it's that full surface structure (shrunken down to contain the active area, but still using the same grid structure) that will be used for the flow, any sort of notches out of the side that are only trim curves won't really have any impact on the flow, as compared to having the full underlying surface itself shaped how you need.

So if you need an irregular boundary you'll want to use something like Loft or Sweep, etc... to construct a full surface that has that structure built into the surface itself - the type of surface you get with Construct > Planar will be a big extended rectangle that then has trim curves on it.

Just wanted to make sure it was clear, it sounds like you have it figured out already though.

- Michael

Hello Micheal,


I did not know that a planar surface is only using trim curves, so thanks a lot for explaining that, it is going to be helpful for future references.


kind regards,
forty

Hi forty, yes for more usual construction it tends to be good to have as simple of a base surface as possible and then any irregular boundaries are trim curves. Constructing things for Flow in particular can be a little different since you sometimes may want a more complex surface since the low level surface structure has a big effect.

Another reason why Construct > Planar builds a trimmed surface is so it can support any kind of complex irregular boundaries like this for example:



It would be extremely difficult to create a single surface that tried to directly follow all the contours of that outline, meanwhile the method of constructing a large base plane that has trims on it is able to do it.

- Michael