[Solved] Formed sticker on non-cylindrical surface

[Takeshi Takahashi]

I'd like to make a formed sticker of 4620859d
https://www.ldraw.org/cgi-bin/ptdetail.c...20859d.dat
to put on a bucket 48245.
https://www.bricklink.com/v2/catalog/cat...7#T=C&C=47

As the side surface of bucket is not cylindrical,
the Pattern Folder web-app by Lasse cannot be used.
Are there any smart ways for creating this sticker,
or should I cut the pattern manually with tweaking the coordinates in LDPE?

Thanks,
Takeshi

[Edit] 2021-06-20
Thanks again for a lot of advice.
The part has been admin-certified and will be included in next release.

[Magnus Forsberg]

I can see 2 ways of doing this.

1)
Use LDPC and import a 3D-mesh as projection data.

2)
Use SlicerPro in either LETGUI or LDPE.

My personal choice would be LETGUI, but I'm often doing things the old shool way.
Both methods will result in some post process clean-up, to get rid of unwanted vertices.

[Philippe Hurbain]

I can see 2 ways of doing this.

1)
Use LDPC and import a 3D-mesh as projection data.

2)
Use SlicerPro in either LETGUI or LDPE.

My personal choice would be LETGUI, but I'm often doing things the old shool way.
Both methods will result in some post process clean-up, to get rid of unwanted vertices.

Using the first method (I'd use that), you may not need postprocessing. But you must set vertices on edges, and triangulate appropriately.

[Takeshi Takahashi]

Yes, I've tried these methods, just like curved printed parts, such as figures and animals.
I've made a mock-up (missing sidewalls and condlines, so not ready for PT).

As it is a projection, the actual sticker shape is stretched and distorted by the surface curvature.
The sticker looks as an exact circle from front view, but it isn't circular when opened-up.
Is it permissible (considering that the formed sticker is only used in a single set)?

[Magnus Forsberg]

Is it permissible (considering that the formed sticker is only used in a single set)?

I think this pattern looks OK, but the shape of the sticker need corrections.

Either move what you've got to LDPE and start manipulating the vertices. Manipulating a single vertex is easy, once you have figured out how to position the Manipulator on a surface or an edge.

Or deform the entire pattern i LDPC prior to the export. Select all triangles, Use the Group function, select the group(Primitive), and make it more narrow. Then the export will "deform" it into a rounder shape

[Philippe Hurbain]

I think this pattern looks OK, but the shape of the sticker need corrections.

Either move what you've got to LDPE and start manipulating the vertices. Manipulating a single vertex is easy, once you have figured out how to position the Manipulator on a surface or an edge.

Or deform the entire pattern i LDPC prior to the export. Select all triangles, Use the Group function, select the group(Primitive), and make it more narrow. Then the export will "deform" it into a rounder shape

I think that in this tricky case we should have used texmap on the bucket in front projection, and tweak the image with Photoshop or Gimp until it looks right, then do the pattern from that image. The good thing is that once this is done we have easily a mixed mode (texmap+triangles) sticker...

[Takeshi Takahashi]

Thanks both.
I'd like to go the way Magnus proposed (horizontally shrink prior to projection) and confirmed it will be a good approximation, as the curvature is not so hard compared with the sticker dimensions.

If there are any objections to make this more perfect, I will calculate the mapped coordinate by Scilab...