Python: Add to_curve method to the object API
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Authored by Omar Emara (OmarSquircleArt) on Feb 7 2021, 10:17 PM.

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Reviewers

Sergey Sharybin (sergey)
Bastien Montagne (mont29)
Brecht Van Lommel (brecht)

Commits

rBf2c0bbed1ce5: Python: Add to_curve method to the object API

Summary

This patch adds a to_curve method to the Object ID. This method is
analogous to the to_mesh method. The method can operate on curve and
text objects. For text objects, the text is converted into a 3D Curve ID
and that curve is returned. For curve objects, if apply_modifiers is
true, the spline deform modifiers will be applied and a Curve ID with
the result will be returned, otherwise a copy of the curve will be
returned. The goal of this addition is to allow the developer to access
the splines of text objects and to get the result of modifier
applications which was otherwise not possible.

Depends on: D10351

Diff Detail

Repository: rB Blender

Event Timeline

Omar Emara (OmarSquircleArt) requested review of this revision.Feb 7 2021, 10:17 PM

Omar Emara (OmarSquircleArt) created this revision.

Harbormaster completed remote builds in B12704: Diff 33688.Feb 7 2021, 10:17 PM

@Sergey Sharybin (sergey) This depends on D10351. Or freestyle could be disabled for testing.

Omar Emara (OmarSquircleArt) edited the summary of this revision. (Show Details)Feb 7 2021, 10:20 PM

Evan Wilson (EAW) awarded a token.Feb 7 2021, 10:45 PM

I think this is a nice and consistent counterpart of to_mesh().

What is a bit weak is the loops which applies modifiers. The current code seems to lack check for tessellation point. Also, should be possible to re-use curve_get_tessellate_point and curve_calc_modifiers_pre.

Additionally, I'd suggest adding an example it doc/ similar to what is done for to_mesh().

Do we really need custom modifier stack evaluation code for this API function? Can't it be shared with existing code?

Promote curve_calc_modifiers_pre to a BKE function.
Split the nurb parameter in BKE_curve_calc_modifiers_pre to a source and target to allow out of place application.
Use BKE_curve_calc_modifiers_pre for modifier application.
Add an example for Object.to_curve() to docs.

Harbormaster completed remote builds in B12719: Diff 33715.Feb 8 2021, 4:02 PM

@Sergey Sharybin (sergey) @Brecht Van Lommel (brecht) I replaced the modifier evaluation loop with curve_calc_modifiers_pre. Is this what you wanted?

Brecht Van Lommel (brecht) accepted this revision.Feb 18 2021, 7:26 PM

Brecht Van Lommel (brecht) added inline comments.

doc/python_api/examples/bpy.types.Depsgraph.7.py
10	curve one -> curve object
15	text one -> text object
16	the apply_modifiers -> apply_modifiers
19–22	result curve -> resulting curve

This revision is now accepted and ready to land.Feb 18 2021, 7:26 PM

In D10354#262414, @Omar Emara (OmarSquircleArt) wrote:

@Sergey Sharybin (sergey) @Brecht Van Lommel (brecht) I replaced the modifier evaluation loop with curve_calc_modifiers_pre. Is this what you wanted?

Yup.