Draw tool draws a 3D curve even though the curve data is 2D #95954

New Issue

jl · 2022-02-22T12:42:07+01:00

jl commented

2022-02-22 12:42:07 +01:00

System Information
Operating system: Linux
Graphics card: intel 520

Blender Version
Broken: (example: 2.80, edbf15d3c0, master, 2018-11-28, as found on the splash screen)
Worked: unknown (new comer to blender)

Short description of error
when drawing a bezier spline using "Draw" in BezierCuve->edit mode in 2D , I get a 3D object with 2 surfaces not in the same plane

Exact steps for others to reproduce the error

(optional) delete all objects
Add a Bezier Curve
Go to Edit Mode
In Object Data Properties make the curve 2D and optionally with Fill Mode Both
Put the view in orthographic
Zoom to the center and rotate the view to a sharp angle so you can see the horizon
Select the Draw Tool and draw a stroke that starts at the bottom and goes to the top of the view.
The resulting curve will be 3D instead of 2D

Original Steps from the report:

Tool Settings :
3d cursor is set to "orientation : geometry" (both using the shift+rightClick or 3d cursor tool)
shift+A is set to create object at 3d cursor location

I select with 3D cursor a face
shift+A -> curves -> bezier
select vertices -> x (erase default curve)
select Draw tool
Object Data Property -> Shape -> 2D
draw something

expected : the 2D curve should be constrained into XY plane of 3D cursor (as when doing shift+A -> Mesh -> plane)

what I get : at best a surface that is "twisted" in 3D, at worst a set of bezier splines linked together and not in same plane (as 2D would make me expect)

additional remarks :

that's too bad that 3d cursor default orientation is View and not object, for a new comer it's really really tricky to understand that and that it's normal that the drawing isn't correctly oriented (it is but in view space, and a view is permanently changing so there is no reproducible behavior)
eula.blend

**System Information** Operating system: Linux Graphics card: intel 520 **Blender Version** Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen) Worked: unknown (new comer to blender) **Short description of error** when drawing a bezier spline using "Draw" in BezierCuve->edit mode in 2D , I get a 3D object with 2 surfaces not in the same plane |![blender2dbezier4.png](https://archive.blender.org/developer/F12882619/blender2dbezier4.png)|![blender2dbezier1.png](https://archive.blender.org/developer/F12882620/blender2dbezier1.png)|![blender2dbezier2.png](https://archive.blender.org/developer/F12882621/blender2dbezier2.png)|![blender2dbezier3.png](https://archive.blender.org/developer/F12882622/blender2dbezier3.png)| | -- | -- | -- | -- | **Exact steps for others to reproduce the error** - (optional) delete all objects - Add a Bezier Curve - Go to Edit Mode - In `Object Data Properties` make the curve `2D` and optionally with `Fill Mode` `Both` - Put the view in orthographic - Zoom to the center and rotate the view to a sharp angle so you can see the horizon - Select the Draw Tool and draw a stroke that starts at the bottom and goes to the top of the view. The resulting curve will be 3D instead of 2D --- **Original Steps from the report:** Tool Settings : 3d cursor is set to "orientation : geometry" (both using the shift+rightClick or 3d cursor tool) shift+A is set to create object at 3d cursor location - I select with 3D cursor a face - shift+A -> curves -> bezier - select vertices -> x (erase default curve) - select Draw tool - Object Data Property -> Shape -> 2D - draw something expected : the 2D curve should be constrained into XY plane of 3D cursor (as when doing shift+A -> Mesh -> plane) what I get : at best a surface that is "twisted" in 3D, at worst a set of bezier splines linked together and not in same plane (as 2D would make me expect) additional remarks : - that's too bad that 3d cursor default orientation is View and not object, for a new comer it's really really tricky to understand that and that it's normal that the drawing isn't correctly oriented (it is but in view space, and a view is permanently changing so there is no reproducible behavior) [eula.blend](https://archive.blender.org/developer/F12882618/eula.blend)

jl commented

2022-02-22 12:42:07 +01:00

Added subscriber: @WoL

blender-admin commented

2022-02-22 12:42:07 +01:00

#95955 was marked as duplicate of this issue

Omar Emara commented

2022-02-22 14:51:42 +01:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-02-22 14:51:42 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Omar Emara commented

2022-02-22 14:51:42 +01:00

Aren't 2D curves locally constrained to the XY plane and thus can't arbitrary aligned with a surface when drawing?
The provided files doesn't seem to be related to the issue. Can you upload the correct file or simplify the file to only contain the objects related to the issue in question?
You should also test on a more recent version of Blender as 2.80 is no longer maintained.

Aren't 2D curves locally constrained to the XY plane and thus can't arbitrary aligned with a surface when drawing? The provided files doesn't seem to be related to the issue. Can you upload the correct file or simplify the file to only contain the objects related to the issue in question? You should also test on a more recent version of Blender as 2.80 is no longer maintained.

jl commented

2022-02-23 10:58:28 +01:00

sorry I thought I filled the version, I use blender 3.0.1

for my knowledge how can I constrain a locally a curve to a plane?

the produced curves aren't in any plane, in the screenshots I provided, the 2nd one it what i see when drawing the 2d curve, the 3rd one is what is got after hiding the other object that is used as reference and rotating the view, the last one is what I see I go into side view of the "2d" spline (if it was 2d, I would only get a line....

here is a simplified blend file, with 2 2d bezier curves drawn using the method given{F12883971}

here is another screenshot with the reference object, 3d cursor and the "2d spline", viewpoint is perpendicular to the 3d cursor XY plane (the drawing plane)

sorry I thought I filled the version, I use blender 3.0.1 for my knowledge how can I constrain a locally a curve to a plane? the produced curves aren't in any plane, in the screenshots I provided, the 2nd one it what i see when drawing the 2d curve, the 3rd one is what is got after hiding the other object that is used as reference and rotating the view, the last one is what I see I go into side view of the "2d" spline (if it was 2d, I would only get a line.... here is a simplified blend file, with 2 2d bezier curves drawn using the method given{[F12883971](https://archive.blender.org/developer/F12883971/eula-2dspline_error.blend)} here is another screenshot with the reference object, 3d cursor and the "2d spline", viewpoint is perpendicular to the 3d cursor XY plane (the drawing plane) ![2dspline.png](https://archive.blender.org/developer/F12883995/2dspline.png)

Philipp Oeser commented

2022-02-23 11:22:00 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Omar Emara commented

2022-02-23 11:25:58 +01:00

It is weird because I can't create 2D curves that are not on the XY plan myself. The documentation also specify that, so it is unclear to me how that's possible https://docs.blender.org/manual/en/2.79/modeling/curves/properties/data.html#shape.
Investigating.

It is weird because I can't create 2D curves that are not on the XY plan myself. The documentation also specify that, so it is unclear to me how that's possible https://docs.blender.org/manual/en/2.79/modeling/curves/properties/data.html#shape. Investigating.

Omar Emara commented

2022-02-23 11:34:14 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Omar Emara commented

2022-02-23 11:34:14 +01:00

I can see the problem in the file you provided, but that curve seems to be corrupted. Are you able to reproduce the issue from scratch on version 3.0+?

jl commented

2022-02-25 15:11:47 +01:00

I closed blender,
restarted from scratch using blend file provided in intial report,

moved the 3d cursor using 3d cursor tool, seems that the setting "orientation : object" was lost... (how can I set it so that it's the default?)
shift+a->bezier, x->vertices, select draw tool, (again how can I set the default of bezier curves to be "2d, filled both sides"?)
drawn again, seems that the 3 tries I've done are drawn into 3d cursor XY plane.... O_o

but I can't be sure... how can I set up "front/left/right/back" views to be in 3d cursor's space (front = 3d cursor XY plane and so on...) ?
same how can I set the view to be "centered on 3d cursor" so that rotating rotate around 3d cursor? '/' center on object's center-point but I don't find it convenient

so, it seems that the bezier draw tool in 2d filled works now as expected and I don't know how I ended with have it missbehave, maybe should give a try with the simplified blend file?

I closed blender, restarted from scratch using blend file provided in intial report, 1. moved the 3d cursor using 3d cursor tool, seems that the setting "orientation : object" was lost... (how can I set it so that it's the default?) 2. shift+a->bezier, x->vertices, select draw tool, (again how can I set the default of bezier curves to be "2d, filled both sides"?) 3. drawn again, seems that the 3 tries I've done are drawn into 3d cursor XY plane.... O_o but I can't be sure... how can I set up "front/left/right/back" views to be in 3d cursor's space (front = 3d cursor XY plane and so on...) ? same how can I set the view to be "centered on 3d cursor" so that rotating rotate around 3d cursor? '/' center on object's center-point but I don't find it convenient so, it seems that the bezier draw tool in 2d filled works now as expected and I don't know how I ended with have it missbehave, maybe should give a try with the simplified blend file?

Omar Emara commented

2022-02-25 16:23:32 +01:00

2D curves in Blender can only exist in the local XY plan of the curve object, I am not sure how you ended up with a 2D curve that is not flat, but even moving a vertex in that curve you provided projects it on the XY plan.
It could be that the curve is corrupt somehow. If we can't replicate that from scratch, I am afraid there isn't much we can do. Can you do that now?

2D curves in Blender can only exist in the local XY plan of the curve object, I am not sure how you ended up with a 2D curve that is not flat, but even moving a vertex in that curve you provided projects it on the XY plan. It could be that the curve is corrupt somehow. If we can't replicate that from scratch, I am afraid there isn't much we can do. Can you do that now?

jl commented

2022-02-27 20:32:50 +01:00

yes it can be reproduced from scratch

download the eula-2dspline error.blend I provided
remove all the bezier spline
move the 3d cursor to some flat surface with 3dcursor's Z pointing at normal
shift+a -> curves -> bezier
x->vertices
change to 2d spline, fill both front and back
draw something with angles

this created EACH TIME a kind of union of 2 2d spline... i tried on the "star looking" surfaces or on some surface between the 2....

yes it can be reproduced from scratch 1. download the [eula-2dspline error.blend](https://archive.blender.org/developer/F12883971/eula-2dspline_error.blend) I provided 2. remove all the bezier spline 3. move the 3d cursor to some flat surface with 3dcursor's Z pointing at normal 4. shift+a -> curves -> bezier 5. x->vertices 6. change to 2d spline, fill both front and back 7. draw something with angles this created EACH TIME a kind of union of 2 2d spline... i tried on the "star looking" surfaces or on some surface between the 2....

Omar Emara commented

2022-02-27 20:52:14 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Germano Cavalcante commented

2022-02-28 21:07:30 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-02-28 21:07:30 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Germano Cavalcante commented

2022-02-28 21:07:30 +01:00

I was able to reproduce the problem from scratch using much simpler steps. I'll edit the description of the report...

Germano Cavalcante changed title from ~~draw 2d bezier not in plane~~ to Draw tool draws a 3D curve even though the curve data is 2D

2022-02-28 21:24:11 +01:00

Philipp Oeser removed the

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Draw tool draws a 3D curve even though the curve data is 2D #95954