Maniphest T81626

Jagged spikes on font with bevel
Closed, ArchivedKNOWN ISSUE
Actions

Assigned To
Campbell Barton (campbellbarton)
Authored By
Henry (Skippi)
Oct 11 2020, 1:17 PM
Tags
  • BF Blender
  • Modeling
Subscribers
Campbell Barton (campbellbarton)
Hans Goudey (HooglyBoogly)
Henry (Skippi)
Philipp Oeser (lichtwerk)

Description

System Information:
Operating system: OpenSuSe Tumbleweed Linux
Graphics card: RTX 2070 super

Blender Version:
Broken: (2.91.0, October 10, 23:20:33- 1b04eb6c4443, as found on the Buildbot Page)
(It is also broken in 2.90 and possibly earlier)

Short description of error:
When applying a bevel to a font, acute angles of the font curve cause large jagged spikes in the bevel. The smaller the angle, the larger the spike.

Exact steps for others to reproduce the error:

  1. Create font object & type some text
  2. Choose a cursive/script font (Though noticeable in bfont too (the 'm'))
  3. Apply a bevel (most obvious when a linear bevel is used (either from object or from profile))
  4. Notice jagged spikes

A .blend file has been attached showing 4 different fonts of varying severity

Example.blend1 MBDownload

Related Objects

Mentioned Here
T80979: Account for curvature in curve to mesh node
rB1b04eb6c4443: Exact Boolean: let Collection be empty.

Event Timeline

Henry (Skippi) created this task.Oct 11 2020, 1:17 PM
Philipp Oeser (lichtwerk) changed the task status from Needs Triage to Confirmed.Oct 12 2020, 1:41 PM
Philipp Oeser (lichtwerk) added a project: Modeling.
Philipp Oeser (lichtwerk) added subscribers: Hans Goudey (HooglyBoogly), Philipp Oeser (lichtwerk).

Can confirm the behavior, without looking at code, this might very well be a limitation of the current code though.

CC @Hans Goudey (HooglyBoogly)

Hans Goudey (HooglyBoogly) changed the subtype of this task from "Report" to "Known Issue".Oct 13 2020, 1:41 AM

Yeah, this is definitely not a new issue. I don't think the curve bevel code was made to handle the sorts of sharp corners that are very common in text.

After playing with some of the examples with the fonts that @Henry (Skippi) provided, my hunch is that this is actually the same issue as T80979, which is just that the bevel size needs to be adjusted based on the angle at every particular point along the curve.

I think it makes sense to make this a known issue since the two issues aren't that related on the surface. If resolving T80979 resolves this report, this can be closed too.

For anyone unfamiliar with how Blender triangulates the "Text" objects, they're actually just curves in the code, with a fill type of "half". You can see this if you convert the text object to a curve object.

Campbell Barton (campbellbarton) closed this task as Archived.Oct 13 2020, 8:31 AM
Campbell Barton (campbellbarton) claimed this task.
Campbell Barton (campbellbarton) added a subscriber: Campbell Barton (campbellbarton).

Rather close this, since this is working as intended and doesn't help us to have more open issues without an obvious outcome.

If there is interest to add options to mitigate these spikes, that can always be developed.