GSoC Roundup Episode Three: Ahead of the Curve, On the Cutting Edge

The 2021 Google Summer of Code projects have just wrapped up, concluding ten weeks of Blender development over eight projects helmed by students and supervised by members of the Blender development team. This is the third post in a four-part series exploring what the students have achieved during this yearโ€™s development stint.

Episode Three: Ahead of the Curve, On the Cutting Edge


While the second post of the series explored the GSoC projects dealing with the VSE and the UV Editors, this third and penultimate post will go through the two projects aiming to improve a fundamental element of any DCC software: Modelling. More specifically, these projects tackle two areas and tools that are at the foundation of many modeling workflows. Dilith Jayakody was at the head of the Curve Improvements project, while Cian Jinks was responsible for the Knife Tool Improvements project.


Curve Improvements

Straight Shooter

Under the supervision of project mentors Hans Goudey and Falk David, Dilith Jayakody aimed to improve the manipulation and creation of Blender curves, an area which the student had already contributed to before the beginning of the summer. As per the project proposal, Dilith ended up implementing two major new features at the end of his GSoC tenure:

Curve Fillet Node

Initially planned to be a regular tool, Dilith opted to implement this feature as a Geometry Nodes node at the recommendation of mentor Hans Goudey, this implementation having the same functionality but benefiting from(and to) the procedural breadth of the system. The goal of this node is to be able to create and control bevel-like rounding of curves at control points. Learn More.

The Curve FIllet node’s different options in action

The Curve Fillet Node patch is ready for you to play with in the latest builds of Blender 3.0 Alpha!

Curve Pen Tool

The goal of the pen tool is to overhaul the curve editing and creation process, by concentrating old and new curve editing functionality and shortcuts into a single tool. Learn More.

The Curve Pen tool makes the creation and editing of curves a breeze

What comes next

Aside from working on getting these two patches merged with master, Dilith will be looking at implementing further improvements to the Curve Pen tool, including snapping support, vertex slide, and more.


Knife Tool Improvements

Sharp as a Knife

The brainchild of student Cian Jinks, the Knife Improvements project holds the distinction of being fully merged with master, meaning that all the features discussed below are already available in the latest Blender 3.0 daily builds! Under the supervision of mentor Howard Trickey, Cian aimed to implement a plethora of features upgrading the Knife Tool’s usability and power. While the student’s final report and patch description hold all the details on the newly implemented features, here is a rundown of some of the standouts:

Visible Distance and Angle Measurements

Pressing S will enable measurements, and pressing S repeatedly will cycle between the three modes: Only Distance, Only Angles, Both. Learn more.

Cian’s Knife Tool improvements include the ability to show measurements and angles between cut segments and mesh edges.

Constrained Angle Mode Improvements

Added setting to control increments, ability to enter snapping angle increment via number keys, and a new local constrained angle mode. Learn more.

The new local constrained angle mode in action

Multi-Object Edit Mode

The Knife tool can now cut through multiple objects in edit mode. Learn more.

Takes the local orientation of the object the cut segment was started on.

Undo Improvements

Pressing Ctrl-Z undoes the previous cut segment and re-adjusts starting point for the current cut segment. Learn More.

The knife tool now supports expected undo behavior.

Snapping to Global and Local Orientation

Press X, Y, Z, to constraint to an axis. Press the axis key again to toggle between Local/Global orientation. Respects scene orientation setting if set, allowing for custom orientations. Learn More.


Join us next week for the last episode of the GSoC Roundup, where we will take a look at the final two projects tackling Blender physics!

Find out more on these two projects on the links below:

14 comments 8,141 Views
  1. Very excited to see this! Thanks so much to those who worked on these additions. You guys have done so well on this, do you think improved NURBS would be another project to tackle?

  2. Thank you! The curve pen tool is a very promising project, as working with curves always has felt strange and slow in Blender, compared to other Software, but PLEASE could you consider making the modifier shortcuts line up with industry standard vector tools like Illustrator, PS, Affinity Designer:

    shift LMB: constraints to 45 degrees,
    single left click: single point with no handles,
    LMB-drag: Bezier Point
    Alt LMB: free single handle,
    Space LMB: move entire point

    or at least make them editable? It is really counterintuitive and frustrating having to use different shortcuts for pratically the same actions.

    • Hi Martin. Sorry about the late response and thank you for the feedback. I understand your concerns. Unfortunately, it was quite challenging to settle on this set of key bindings because it’s easy to get overlapping shortcuts. For example, `Alt LMB` is also used by Blender for emulating the three-button mouse so it’s not an option to have it as default. However, I’ll try to provide the option for custom key-bindings where possible. There will likely be some changes that happen during the code reviews.

  3. Yes, you ‘Knifed it’ ! ๐Ÿ˜€

  4. The Knife Tool still doesn’t feel right to me, would the students continue working on these or they’ll let go once the project gets merged?

  5. Blender Geometry Nodes is one of the professional things blender. more right click select ideas of the Geometry Nodes category should be implemented.

  6. Looking good, but I think the current hair particle system is pretty dated and should be a priority to revamp.

  7. That moment when improvements on old features are more exciting than “flashy” new ones.

  8. Hey its awesome how every year the GSOC just improves so much.. And last year, ig the addition of colors in collection was one of those.
    I had a suggestion : At the beginning the blog, its written `Episode Two : Ahead of the Curve` which I believe should be Episode Three : Ahea….

  9. don’t know how to upload pictures so:

    https://blender.community/c/rightclickselect/MZWP/

    I hope it is a good place here .. and does not come off badly.

    thank you all for the great work!!

    cheers ๐Ÿ™‚

    • Use blenderartists for questions as it is highly unlikely to be a bug.

  10. Cool stuff…
    Can’t wait for the Pen Tool… ๐Ÿ‘Œ

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