Overview
This lecture covers custom 3D modeling in Blender, focusing on the basics of mesh construction, essential edit mode tools, selection methods, and step-by-step modeling of multiple basic objects.
Mesh Construction Basics
- 3D models are built from polygons, which typically have four edges and four vertices (quads).
- Faces can also be triangles (three vertices), but quads are preferred for clean topology.
- Each face has a normal, used for shading, which is perpendicular to the face.
- Vertices and edges are primarily used to build and manipulate meshes.
Edit Mode Operations
- Switch between Object and Edit Mode using Tab.
- In Edit Mode, you can manipulate vertices, edges, and faces:
- 1 = Vertex select, 2 = Edge select, 3 = Face select.
- Use G (move), S (scale), R (rotate) on selected elements.
- Use E to extrude selected faces/edges/vertices and Ctrl+R for loop cuts (additional geometry).
- Ctrl+B applies bevels/chamfers to selected edges or faces.
- Delete key removes faces, edges, or dissolves geometry as needed.
Mesh Modification Tools
- Subdivision Surface modifier (Smooth) increases mesh resolution and roundness.
- Edge proximity impacts mesh smoothness: closer edges produce sharper corners.
- Shade Smooth and Shade Flat alter how mesh surfaces display without changing actual geometry.
Selection Techniques
- Shift-click to select multiple elements; Alt-click selects loops/rings.
- Ctrl-click selects shortest path between elements; Ctrl+I inverts selection.
- Box (B), Circle (C), and random selection available for efficiency.
- Select Sharp Edges isolates edges above an angle threshold.
- Non-manifold and loose geometry selection helps identify mesh errors.
Proportional Editing & Linked Selection
- Proportional Editing (O) enables smooth, "soft" selection, affecting connected geometry in a radius.
- Adjust influence with mouse scroll; connected-only limits effect to contiguous geometry.
- L selects all linked elements within a mesh.
Essential Edit Mode Tools
- Extrude (E), Insert (I), Bevel (Ctrl+B), Loop Cut (Ctrl+R), Knife (K), Bisect.
- Edge Slide, Shrink/Flatten, Rip (V), Merge, Bridge Edge Loops, Poly Build, Spin, Smooth, Randomize, Grid Fill.
- Most tools have different modes/options (e.g., extrude along normals, individual, or to cursor).
Modeling Practice (Objects Modeled)
- Step-by-step creation of pencil, sandal, mug, headphones, apple, trumpet, glasses, egg, piggy bank, and banana.
- Emphasizes combining tools and planning geometry for practical modeling.
Rendering & Layout Basics
- Set up camera with Shift+A and Ctrl+Alt+0.
- Use HDR environments for lighting; assign basic materials/colors.
- Link materials across objects with Ctrl+L; render image and save.
Key Terms & Definitions
- Polygon — A face in 3D modeling, usually a quad or triangle.
- Vertex — A point in 3D space forming mesh corners.
- Edge — A line connecting two vertices.
- Face/Polygon — The flat surface area bounded by edges.
- Normal — A perpendicular vector to a face, used in shading.
- Extrude — Extending geometry in a specified direction.
- Loop Cut (Ctrl+R) — Adds an edge loop for more mesh detail.
- Bevel (Ctrl+B) — Rounds or chamfers edges or faces.
- Proportional Editing (O) — Soft-selects and transforms mesh areas with a falloff.
- Subdivision Surface — Modifies mesh for more smoothness and detail.
Action Items / Next Steps
- Practice modeling 5-10 basic objects using the tools discussed.
- Experiment with selection, transformation, extrusion, and modifiers.
- Prepare a simple render with camera, lighting, and basic materials.
- Read/review the next chapter focusing on modifiers.