B-Spline Constraints: Fully Funded! Thanks everybody!

Info about new community or project announcements, implemented features, classes, modules or APIs. Might get technical!
PLEASE DO NOT POST HELP REQUESTS OR OTHER DISCUSSIONS HERE!
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
User avatar
jnxd
Posts: 951
Joined: Mon Mar 30, 2015 2:30 pm
Contact:

Re: B-Spline Constraints: Looking for Crowdfunding

Post by jnxd »

FUNDING UPDATE: 15 October 2022

Since the release of the fundraiser, I have received:

Github:
One time: $630
Monthly: $7

Liberapay:
Directly to me: $89 + €155 = ~$244
As part of FreeCAD Liberapay team: $74 + €114 + NZ$156 = ~$275

Additional:
Pledged: $40 + €250
Grant from FPA: $1000

All in all, this amounts to up to ~$2460/$3000 towards this project, taking 3 months of the monthly contributions.

Contributions had been relatively stagnant since the last update, but a good few came in once after the winding down plan and social media posts.

If you had been waiting for the project to complete before funding, I'd suggest now is a good time. I would like to make the last PR after the funding is complete, but even otherwise the merge can take its time depending on any bug discoveries and reviewers' free time.

I'd also like to ask interested people to share the updates on this project, especially in places where I can't do so myself, like non-English forums.
My latest (or last) project: B-spline Construction Project.
chrisb
Veteran
Posts: 53920
Joined: Tue Mar 17, 2015 9:14 am

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by chrisb »

I asked for support in the German forum.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
User avatar
jnxd
Posts: 951
Joined: Mon Mar 30, 2015 2:30 pm
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by jnxd »

chrisb wrote: Sat Oct 15, 2022 10:03 pm I asked for support in the German forum.
Thanks!
My latest (or last) project: B-spline Construction Project.
User avatar
uwestoehr
Veteran
Posts: 4961
Joined: Sun Jan 27, 2019 3:21 am
Location: Germany
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by uwestoehr »

@jnxd , I had now time to test your work properly. What should I say? Amazing! :D

Once I wrote the https://wiki.freecadweb.org/B-Splines I created some test files to play around. Everything works fine wtih them.

I have only one question: When I move a knot, why does the weight of all control points change?:
FreeCAD_DefZlXUILu.gif
FreeCAD_DefZlXUILu.gif (469.21 KiB) Viewed 37733 times
I expected that the weight is not changes at all since the movement of a point keeps the spline rational in my example even all weights are equal therefore a weight change has no effect either.

Here is my test file:
Spline-test2.FCStd
(7.12 KiB) Downloaded 24 times
User avatar
jnxd
Posts: 951
Joined: Mon Mar 30, 2015 2:30 pm
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by jnxd »

uwestoehr wrote: Sun Oct 16, 2022 12:35 am

I have only one question: When I move a knot, why does the weight of all control points change?:
FreeCAD_DefZlXUILu.gif

I expected that the weight is not changes at all since the movement of a point keeps the spline rational in my example even all weights are equal therefore a weight change has no effect either.

Here is my test file: Spline-test2.FCStd
The weights are not changing, just the physical representations, viz. radii of the circles. See the radius constraint on the first pole (with all the equalities). This was done before my time, probably so that the circles are visible however large or small the spline. Ideally this should change by the size of the screen. @abdullah probably will be in a better place to talk about it, as much as I hate to add another tag to his pile.

You could try this: save the document with the changed knot, and open it in master. The weight circles should be the same new size. Then try dragging back the poles to their original place and see the circles get back to the old size. You will need to change 3 control points.
My latest (or last) project: B-spline Construction Project.
abdullah
Veteran
Posts: 4935
Joined: Sun May 04, 2014 3:16 pm
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by abdullah »

jnxd wrote: Sun Oct 16, 2022 3:09 am The weights are not changing, just the physical representations, viz. radii of the circles. See the radius constraint on the first pole (with all the equalities). This was done before my time, probably so that the circles are visible however large or small the spline. Ideally this should change by the size of the screen. @abdullah probably will be in a better place to talk about it, as much as I hate to add another tag to his pile.

You could try this: save the document with the changed knot, and open it in master. The weight circles should be the same new size. Then try dragging back the poles to their original place and see the circles get back to the old size. You will need to change 3 control points.
Indeed. The physical size of the circle depends on the size of the B-Spline (try in master to move the endpoints of a B-Spline and you will see the circles change size to account for the size of the B-Spline). There needs to be a mapping between the adimensional weight magnitude and a length for representation. The current mapping is understood to provide a representation commensurate with the size of the B-Spline within the screen area.
User avatar
uwestoehr
Veteran
Posts: 4961
Joined: Sun Jan 27, 2019 3:21 am
Location: Germany
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by uwestoehr »

abdullah wrote: Sun Oct 16, 2022 4:54 am Indeed. The physical size of the circle depends on the size of the B-Spline
That is reasonable, but in my screenshot you see that the circles increase also when I just move within the outline of the spline. I thought the circles will only start to increase when the overall size (meaning the bounding box/outline box) is changed.

However, I understand that this is independent of @jnxd's work.
abdullah
Veteran
Posts: 4935
Joined: Sun May 04, 2014 3:16 pm
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by abdullah »

uwestoehr wrote: Sun Oct 16, 2022 2:48 pm
abdullah wrote: Sun Oct 16, 2022 4:54 am Indeed. The physical size of the circle depends on the size of the B-Spline
That is reasonable, but in my screenshot you see that the circles increase also when I just move within the outline of the spline. I thought the circles will only start to increase when the overall size (meaning the bounding box/outline box) is changed.

However, I understand that this is independent of @jnxd's work.
By moving the outline in the way you are doing it, you are increasing the length of the B-Spline. See:
https://github.com/FreeCAD/FreeCAD/blob ... .cpp#L2553
User avatar
uwestoehr
Veteran
Posts: 4961
Joined: Sun Jan 27, 2019 3:21 am
Location: Germany
Contact:

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by uwestoehr »

abdullah wrote: Sun Oct 16, 2022 4:39 pm By moving the outline in the way you are doing it, you are increasing the length of the B-Spline. See:
https://github.com/FreeCAD/FreeCAD/blob ... .cpp#L2553
Thanks, I understand now. I will add a note to the Wiki.
User avatar
Bernard19
Posts: 887
Joined: Sun Feb 20, 2022 7:16 pm

Re: B-Spline Constraints: Almost Done! Help Reach Goal!

Post by Bernard19 »

I take advantage of your work on B SPline.
My question is when a BSpline is used as an external geometry. We only have end points to lean on and a line. The idea would be to position and snap a point on the line. This possibility is not currently supported, it seems to me. May be there is already a possibility but I don't know it.
Post Reply