Lecture on Geometry Nodes in Blender

Introduction

• Geometry Nodes: A feature in Blender used for procedural modeling and creating complex modifications.
• Accessing Geometry Nodes: Found in the tab at the top of Blender's interface.

Geometry Nodes Basics

• Modifier System: Geometry nodes act as a modifier.
• Node-Based System: Utilizes boxes and lines similar to material nodes but operates differently.
• Workflow: Mesh inputs on the left are processed through nodes and output on the right.

Practical Example: Donut Sprinkles

• Adjusting Layout: Close unnecessary panels like the spreadsheet view for clarity.
• Creating Sprinkles: Use geometry nodes to add and modify features like sprinkles on a donut.

Steps to Add Sprinkles

1. Node Setup: Add 'Set Position' node to adjust mesh positions.
2. Scatter Points: Use 'Point distribute points on faces' to scatter points on the mesh.
3. Retain Original Mesh: Add 'Join Geometry' node to combine original mesh with scatter points.

Instance Creation

• Creating Sprinkles as Instances:
  • Create a base shape (UV Sphere) for sprinkles.
  • Reference this shape in the geometry node system using 'Instances on Points'.

Enhancing Realism

• Avoid Overlapping: Change distribution to Poisson Disc and adjust minimum distance to prevent overlaps.
• Weight Painting:
  • Use weight paint mode to define where sprinkles appear.
  • Reference weight paint in geometry nodes for custom distribution.

Customization and Flexibility

• Exposing Parameters: Drag parameters to the group input to make them adjustable in the modifier stack.
• Unique Object Modifications: Pin nodes to apply different settings to multiple objects sharing the same node group.

Scaling and Real-World Measurements

• Correct Object Scaling: Ensure objects are true to scale for accurate rendering and interactions.
• Apply Scale: Use 'CTRL + A' to apply the scale to objects.

Advanced Techniques

• Density Adjustments: Multiply density settings to maintain efficiency and precision in adjustments.
• Node Customization: Customize node settings and parameters for personalized tools and reliable results.

Conclusion

• Geometry Nodes Power: Enables creating new tools and effects that were previously impossible without scripting.
• Future Topics: Next steps include adding more complex sprinkles and randomizing colors.

Final Thoughts

• Geometry nodes significantly enhance Blender's flexibility, making it a valuable tool for 3D modeling and animation.