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User:OmarSquircleArt/GSoC2019/Proposal

Improve Cycles/EEVEE For Procedural Content Creation

Name

Omar Ahmad

Contact

Synopsis

The project hopes to refactor and add Cycles/EEVEE nodes to improve the workflow of technical/shading artists. This is done by providing; more streamline nodes for vector math and numerical computations, more noise types, and wider access to Blender’s data like object properties and spline info.

Benefits

Faster workflow and less workarounds for procedural content creators.

Deliverables

The projects hopes to achieve the following:

  • Implement dynamic socket hiding for nodes that may benefit from it.
  • Allow variable inputs for the Mapping node. Take care of UI considerations.
  • Provide more vector math operations. Entrywise multiplication, snap, reflect, etc.
  • Provide a random generator, often referred to as White Noise.
  • Provide a Clamp node as an alternative to the Clamp option in the math node.
  • Provide a Map Range node similar to that of the Compositor’s.
  • Provide more basic noise functions based on feedback from the community.
  • Investigate accessing custom properties through the Attribute node.
  • Expose information about splines in a Spline Info node.

Project Details

Dynamic Socket Hiding

Nodes sometimes have sockets that are undefined or unused, this can be confusing for new users and doesn’t look good. A simple solution is to dynamically hide sockets that are not defined or unused. For instance, the sine and cosine functions in the math node don’t use the second input socket and it can be hidden. The same goes for the Vector Math node where the value and vector outputs may not always be defined as in the Dot Product type.

Variable Mapping Inputs

We currently have a Mapping node capable of performing linear transformations. However, this node doesn’t expose the transformation parameters which often leads to the user having to implement custom transformation node groups. We shall allow dynamic inputs for the node to avoid this. Relevant RCS post.

Vector Math Operations

We shall add more vector math operations to avoid frequent separation and recombination of vectors in order to do the simplest of operations. The new operations include:

  • Entrywise Multiplication and Division.
  • Projection.
  • Reflection.
  • Entrywise Absolute.
  • Entrywise Snap.
  • Vector Length.

Relevant RCS post.

Random Generator

We currently have a Noise node, but often we just need a random value based on the input vector. We shall add a random generator node that returns a random number between 0 and 1 based on the input vector. A seed value will be provided. And the output shall be constant for the same seed value.

Clamp Node

Math nodes have a clamp option that clamps the output to the 0-1 range. This option—in my experience—is nearly never used and is limited to that range. The other option is to use two maths nodes with a maximum-minimum configuration. We shall add a Clamp node as an alternative that lets the user define the range.

Map Range Node

The compositor already have a node to perform linear value remapping. We shall implement a similar node for the shading system.

More Noise Types

We shall implement more basic organic noise types. The plan is to ask feedback from the community and implement the noise types they think are essential for their creations. The project shall only implements the noise types that are hard or impossible to create through other means. Relevant RCS post.

Object Properties

We shall allow access to any primitive object property (Numbers, Vectors, and Colors) through the Attribute node. For instance, color would return the color of the object and scale would return the scale of the object. Relevant RCS post.

Spline Info

We shall add a Spline Info node that exposes some information about splines. I explained this in details in my proposal Spline Info.

Project Schedule

I shall finish my final exams on the first of June. At this time, I will start studying the prerequisites of the project, mainly OSL and C++ OOP concepts. The coding timeline would be:

  1. Setup a development environment and compile Blender.
  2. Get familiar with the code base. Learn concepts like RNA and common structures.
  3. Study the backends SVM, OSL, and the process of adding new Cycles/EEVEE nodes.
  4. Implement dynamic socket hiding.
  5. Add the extra Vector Math Operators.
  6. Add Clamp, Random Generator, and Map Range nodes.
  7. Add dynamic sockets to the Mapping node.
  8. Add Spline Info node.
  9. Add more noise types.
  10. Implement Object Properties access through the Attribute node.
  11. Document the development process for future students and developers.
  12. Add documentation.

Biography

I am a 19 years old student in the Faculty of Computers and Information at Helwan University. I have been using Blender for over 6 years. And I worked as a CG Generalist and a Technical Artist for over 3 years. My favourite thing about Blender is Animation Nodes, I love procedural content creation and scientific computation/visualization using Animation Nodes and Cycles. You might call me a “noder” because the node editor is my second home, hence my choice of the project. I also love technical writing and cats.

I gained most of my programming experience by contributing to the Animation Nodes project using Python and Cython. I also created multiple addons for Blender, but I am probably the only one who uses them. So I am experienced in Python and know my way around the API.

I never contributed to an open source project that uses C/C++. But I coded a multitude of small programs using C. I created those programs to practise C, OpenGL, GLSL, X11, and event driven programming in general. You can see some of those on my Github. While I never used C++ before, I am motivated and confident that I will get up to speed with it by the time the project starts. I implemented one of my goals as a demonstration, you can check the patch at D4625.

I spend a lot of my time doing technical writing. I am one of the top users on Blender’s StackExchange network and I wrote the Animation Nodes documentation. So I can write good and efficient documentations.