Improve: Curve Mesh discontinuity with varying point radii #86389

New Issue

Jamell Moore · 2021-03-08T13:10:48+01:00

Jamell Moore commented

2021-03-08 13:10:48 +01:00

I'm creating an animated ribbon gradient for my logo using splines and generated geometry. The ribbon is tapered at the ends by making the radii at the endpoints smaller to achieve the look; but I've ran into and issue with the generated mesh.

Issue

When creating a mesh from a curve using the geometry options, with varying point radii, the generated mesh becomes discontinuous at the point regions.

Steps to Reproduce

Create V shaped Bezier curve that is symmetrical across the y axis
Set all of the handles to automatic
Give the curve some thickness by generating a mesh through the Bezier Curve data panel. Set Bezier Curve Data -> Geometry -> Round -> Depth to an appropriate value.
Scale up the radius of the middle point of the curve using the 'Radius' tool

Increase the U resolution from the Bezier Curve Data panel to see the effects at an extreme.

Possible Solution:

Have an option under the geometry section of the curve data properties that when active, will produce a mesh tangent to the curve handles. Or even an option to blend between the two states to get the desired output.

See attached images:

curve-mesh-discontinuity-proposed-improvement.blend

Updated: I'm not sure if discontinuity is the best word to use as all discrete meshes are discontinuous but I think you'll see the issue. If you look at the close up. the top vertex is higher than it ideally should be. The adjacent edge should either be horizontal or sloping upwards from left to right.

I'm creating an animated ribbon gradient for my logo using splines and generated geometry. The ribbon is tapered at the ends by making the radii at the endpoints smaller to achieve the look; but I've ran into and issue with the generated mesh. **Issue** When creating a mesh from a curve using the geometry options, with varying point radii, the generated mesh becomes discontinuous at the point regions. **Steps to Reproduce** - Create V shaped Bezier curve that is symmetrical across the y axis - Set all of the handles to automatic - Give the curve some thickness by generating a mesh through the Bezier Curve data panel. Set Bezier Curve Data -> Geometry -> Round -> Depth to an appropriate value. - Scale up the radius of the middle point of the curve using the 'Radius' tool # Increase the U resolution from the Bezier Curve Data panel to see the effects at an extreme. **Possible Solution:** Have an option under the geometry section of the curve data properties that when active, will produce a mesh tangent to the curve handles. Or even an option to blend between the two states to get the desired output. See attached images: ![curve-mesh-continuity-proposed-improvement.jpg](https://archive.blender.org/developer/F9879230/curve-mesh-continuity-proposed-improvement.jpg) ![curve-mesh-continuity-issue-closeup.jpg](https://archive.blender.org/developer/F9879232/curve-mesh-continuity-issue-closeup.jpg) [curve-mesh-discontinuity-proposed-improvement.blend](https://archive.blender.org/developer/F9879234/curve-mesh-discontinuity-proposed-improvement.blend) Updated: I'm not sure if discontinuity is the best word to use as all discrete meshes are discontinuous but I think you'll see the issue. If you look at the close up. the top vertex is higher than it ideally should be. The adjacent edge should either be horizontal or sloping upwards from left to right.

Jamell Moore commented

2021-03-08 13:10:48 +01:00

Added subscriber: @JamellMoore

Ankit Meel commented

2021-05-17 15:10:25 +02:00

Added subscriber: @ankitm

Ankit Meel commented

2021-05-17 15:10:25 +02:00

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

Ankit Meel commented

2021-05-17 15:10:25 +02:00

Could you add the exact steps to create the curve and the meshes ?
Also, do you intend to add a patch, and are waiting for input from modeling team ?

Could you add the exact steps to create the curve and the meshes ? Also, do you intend to add a patch, and are waiting for input from modeling team ?

Jamell Moore commented

2021-05-19 19:03:11 +02:00

I did have a brief look at the code at the time of original submission and was intended to experiment to see if this could be improved ,but unfortunately I haven't had the time to look into any further.

My original idea wouldn't work but I do believe that the continuity could be improved by introducing some kind of easing to the mesh radius around the points.

I highly doubt that I'm going to be able to pursue this any time soon so feel free to close the task.

I did have a brief look at the code at the time of original submission and was intended to experiment to see if this could be improved ,but unfortunately I haven't had the time to look into any further. My original idea wouldn't work but I do believe that the continuity could be improved by introducing some kind of easing to the mesh radius around the points. I highly doubt that I'm going to be able to pursue this any time soon so feel free to close the task.

Philipp Oeser commented

2021-05-28 10:48:35 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-05-28 10:48:35 +02:00

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

Philipp Oeser closed this issue

2021-05-28 10:48:35 +02:00

Philipp Oeser commented

2021-05-28 10:48:35 +02:00

You can already use a different interpolation method than Linear [which is the default I believe] for Radius and Tilt.

in the Properties Editor:

editmode on the curve
Active Spline panel
change Radius interpolation

#86389.webm

Dont think there is a bug here [or even a patch to submit], everything working as expected here.
Will close, but feel free to comment again if issues persist.

You can already use a different interpolation method than `Linear` [which is the default I believe] for Radius and Tilt. in the Properties Editor: - editmode on the curve - Active Spline panel - change Radius interpolation [#86389.webm](https://archive.blender.org/developer/F10146280/T86389.webm) Dont think there is a bug here [or even a patch to submit], everything working as expected here. Will close, but feel free to comment again if issues persist.

Jamell Moore commented

2021-05-28 11:07:42 +02:00

Thanks for taking the time to point out the interpolation settings Philipp. I'm not sure how I missed those. That's what I was looking to implement but it's already be done, so yeah issue solved.

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Improve: Curve Mesh discontinuity with varying point radii #86389

Increase the U resolution from the Bezier Curve Data panel to see the effects at an extreme.