Unofficial File p/9-16cyli.dat
part image
File Header:
0 Cylinder 0.5625
0 Name: 9-16cyli.dat
0 Author: Santeri Piippo [arezey]
0 !LDRAW_ORG Unofficial_Primitive
0 !LICENSE Redistributable under CCAL version 2.0 : see CAreadme.txt

0 BFC CERTIFY CCW

Status:
Needs more votes. (CN)
Size: 1425 bytes
Reviewers' certifications:
MagFors=certify
arezey=novote
Required (unofficial) subfiles:
(none)
Related (unofficial) subfiles:
Cylinder Open 0.5625
Status: 1 subfile isn't certified. (CSN)
Download: p/9-16cylo.dat
~Technic Bionicle Weapon Pincer 7 x 12 - Half
Status: 3 subfiles aren't certified. (SSSN)
File reviews and updates:
At Sat Feb 10 16:05:00 2018, the file was initially submitted.
Submitted by: arezey
At Thu Mar 15 21:30:00 2018, the following review was posted:

Reviewer: MagFors
Certification: hold
Comments:
Please use PrimGen2 to make cylinders too.
This file is not made correctly. First and last cond-line have non-tangential control points.
Trailing zero at file end.

At Fri Mar 16 07:40:00 2018, the following review was posted:

Reviewer: arezey
Certification: novote
Comments:
Hmm, I derived this from an official cylinder primitive by removing quads and edges until it was correct. Does this mean that official cylinders are also wrong?

At Fri Mar 16 19:30:00 2018, the following review was posted:

Reviewer: MMR1988
Certification: hold
Comments:
No, official cylinders have the first and last condline tangential. If you reuse an parts of an official cylinder you need to change the outer condlines. That's all.

At Fri Mar 16 20:40:00 2018, a new version of the file was submitted.
Submitted by: arezey
Comments:
I really am on a spree on completely missing obvious things. I only made this primitive after specifically checking whether primgen2 was able to make cylinders, yet I didn't see the "Cylinder" in the combo box...

Regenerated.

Existing certification-votes were deleted.
At Fri Mar 16 20:40:00 2018, the following review was posted:

Reviewer: arezey
Certification: novote
Comments:
@Max: thanks for the explanation. What does "tangential" mean here, and how does that differ from the other conditional edges between the surfaces of cylinders?

At Sat Mar 17 10:35:00 2018, the following review was posted:

Reviewer: MagFors
Certification: certify
Comments:
I once made this picture trying to explain complementary cond-lines.
http://www.brickshelf.com/gallery/MagFors/LDraw/pictures/Errors/image_10.png

The first and last cond-lines in a sectional cylinder (and cone) primitive,
should always have a control point in a tangential direction from the circle.
Two sectional cylinder primitives placed on the same origin will complement each other, with overlapping condlines.
This also explains why you always have to add a complementary cond-line, when the next
surface isn't part of a curved primitive, unless it is placed in the tangential plane of the cond-line.

Look at the cond-lines in a half-sphere placed on top of a cylinder, or a torus used between two cylinder, creating a bent cylinder.