User:FabianSchempp/Proposal

Porting popular modifiers to Geometry Nodes

Name

Fabian Schempp

Contact

Email: fabianschempp@googlemail.com developer.blender.org: fabian_schempp Blender.chat: fabian_schempp

Synopsis

For a long time, the modifier system was the main way to procedurally generate and modify 3D data in Blender. While modifiers can be stacked to produce a large variety of results it has limited control over the flow of data. The Geometry Nodes system, introduced in version 2.92 of Blender allows the user to go way beyond these limitations by building complex processing graphs with an advanced attribute system that allows storing data into geometry to be available for later nodes in the graph to operate on. At the time of writing, only a small set of basic functionality is available as nodes. This project will port a selection of functionality from the old modifier system to the new nodes system, taking into account the atomic design, the attributes system, and the variety of geometry types it operates on.

Benefits

The currently available set of nodes mainly focuses on set decoration via point instancing and basic math operations. This is already very powerful and people use it to create an unexpected variety of results, but it lacks much of the functionality that is available for the modifier system. The potential to create stunning procedural 3D content will grow exponentially with each new node this project adds to the system. Additionally, since the existing modifiers are mostly limited to be used on mesh data, users will benefit from the ability to use the ported functionality with other geometry types like Volumes, Point Clouds and Instances in a consistent way.

Deliverables

Proper port of the functionality of the following modifiers to the new Geometry Nodes system (In order of priority): Smooth Solidify Remesh Decimate Bisect (optional)

Existing Modifiers will be split up into several atomic nodes where it is appropriate. Nodes will support different available geometry types (Mesh, Point Clouds, Volume, Instance) where possible. New nodes will be tested and supplied with developer and user documentation.

Project Details

  1. Analyse
    Analyse existing modifiers and their functioning, by looking at the interface and codebase.
  2. Design
    1. Dissect functionality from each modifier into smaller more atomic pieces where possible and appropriate.
    2. Adapt the pieces of functionality to properly fit into the attribute system and work with additional geometry types.
    3. Create a visual layout for each of the nodes UI that can be discussed and refined. NOTE: Some basic design is already supplied on wiki.blender.org and developer.blender.org. General overview: developer.blender.org/T86839
      Smooth Node: developer.blender.org/T86903
  3. Implementation
    After discussion and refinement, the nodes will be implemented and tested one after another. Each new node will be supplied and made available for review as a single patch on developer.blender.org
  4. Documentation
    User documentation will be supplied for each new node. Preliminary Thoughts Since I already have a fully working environment setup for Blender I don’t have to take this into account in my Schedule. I already worked on implementing new nodes for Geometry Nodes and also worked in more depth with the UI system, so adding new nodes and building the user interface should be a straightforward process. For porting the old functionality of the modifier the main work should be to decide how to handle code duplication between modifiers and nodes and in fitting it to the new attribute system. Since Geometry Nodes are written in C++ transferring existing C code to C++ may also be desirable. Making the functionality work on other geometry types will require additional thoughts and exploration and therefore a greater portion of the time spend. Where existing modifiers used the concept of vertex groups to mask influence, attributes can be used in the Geometry Nodes system. developer.blender.org/T86907 There is already an unfinished and abandoned patch for a Remesh node on developer.blender.org. Where possible I would use this as a base.

Project Schedule

Until June 7

Spend some time to understand how other geometry types like volumes and instances are processed in existing nodes to get a better understanding of how to apply existing functionality to these new types.

Week 1

Study the code and the UI of Smooth, Solidify, Remesh and Decimate modifier to get a detailed overview of the functionality, talk to the community and developers to collect additional opinions and ideas, and consolidate what I learn into design and mockups for the new nodes.

Week 2 + 3

Implementation of the functionality derived from the Smooth modifier followed by testing, refinement, and documentation.

Week 4 + 5

Implementation of the functionality derived from the Solidify modifier followed by testing, refinement and documentation.

Week 6 + 7

Implementation of the functionality derived from the Remesh modifier followed by testing, refinement, and documentation.

Week 8 + 9

Implementation of the functionality derived from the Decimate modifier followed by testing, refinement, and documentation.

Week 10

Keep the last week as a time buffer and for additional cleanup.

Bio

I’m Fabian Schempp. With the initial motivation to make video games, I started my career in programming, design, and 3D at the age of 9 Years. After I learned to use 3d studio max and Maya I had my first contact with Blender version 2.43 in 2007 and instantly fell in love with it. Since this day, I have used Blender for uncountable personal and professional Projects. Over time my interest shifted from creating content myself to creating tools that enable others to create content. After I finished my bachelor's and master's degree in user experience design at the University of Applied Sciences in Wiesbaden. I had a one-year stipend at Fraunhofer-Institut for graphical data processing in Darmstadt, where I worked on an AR remote interface. Followed by some years as a freelance developer and UX designer where I had the chance to work on some projects in the field of machine learning, VR, and procedural 3d data generation for Siemens. I’m currently studying Computer Science at the University of Hagen in Germany. I’m confident with the most popular programming and scripting languages including C, C++, Python and GLSL. I'm familiar with most aspects of Blender and its history. Since the end of 2020, I contributed some patches to the Geometry Nodes Project including the Multi-Input-Socket. I’m an active member of Blender's Nodes & Physics Module.