Digital Media Design · Bronx International High School
The Dimensional Path
A 3D Design & Printing Study Book
8 chapters · TinkerCAD, Fusion 360, Onshape, Blender & real 3D printing
Digital Media Design · Bronx International High School
A 3D Design & Printing Study Book
“The Dimensional Path” is Book Eight in this Digital Media Design series, written by a teacher at Bronx International High School for his own students and provided to them entirely free of charge. Like The Experience Path, this book isn't aligned to a single software certification exam — there isn't one that covers all four tools this book teaches. Instead, it's organized around a real skill progression: understanding 3D space itself, understanding what CAD software actually does, hands-on work in four real, current tools that each teach a different approach, and finally turning a digital model into a real, physical object on this classroom's own printers.
You are free to copy, share, print, and adapt this book, for any educational purpose, at no cost to anyone — on the following conditions: attribution required; non-commercial only; always free. Same license as every other book in this series.
This book deliberately teaches four different 3D tools instead of just one, because they genuinely aren't interchangeable — each represents a real, different approach used by real working designers: TinkerCAD (the beginner on-ramp), Fusion 360 and Onshape (two different takes on professional, precision parametric CAD), and Blender (a completely different paradigm built for organic, artistic 3D work rather than engineered parts). All four are free for students as of this writing (verified September 2026) — TinkerCAD and Blender fully free, Fusion 360 and Onshape through their respective education programs.
Chapter One
01
Every 3D tool in this book asks you to think in a way that's genuinely different from 2D design — not harder, exactly, just different, and worth building deliberately before opening any software.
This chapter covers the real vocabulary of 3D space, how designers represent 3D objects on a flat page, and how the drawing fundamentals from Paper First already started building this skill.
Every point in 3D space is described by three numbers along three perpendicular directions — the foundation every single tool in this book is built on top of.
| X-Axis | Conventionally, left-right (width). |
| Y-Axis | Conventionally, front-back (depth) in 3D software — note this is different from 2D design software, where Y usually means up-down. |
| Z-Axis | Conventionally, up-down (height) in most 3D software. |
| Origin | The single point, (0,0,0), that all three axes cross through — every object's position is measured relative to it. |
| Plane | A flat 2D surface within 3D space, defined by two of the three axes (the XY plane, the XZ plane, the YZ plane). |
In Illustrator or InDesign, the Y-axis means up and down. In most 3D software, Z means up and down, and Y means front-to-back depth instead. This isn't a mistake in either program — it's just a different, equally valid convention — but it's worth naming directly here because it causes real, predictable confusion the first time a 2D designer opens a 3D tool and nothing moves the direction they expected.
Draw 3 lines meeting at one point, representing the X, Y, and Z axes, and label each. Place a dot somewhere in the space they create and write its approximate position as 3 numbers (e.g., "3 right, 2 back, 4 up"), the same way real 3D coordinates work.
Long before any computer existed, designers and drafters solved the real problem of showing a 3D object accurately on flat paper — and these same conventions are exactly what every 3D tool's viewport is doing on screen.
| Orthographic View | A flat, straight-on view of one side of an object (front, top, side) with no perspective distortion — used for precise, measurable technical drawings. |
| Isometric View | A 3D-looking view where all three axes are shown at equal angles (120° apart), giving a realistic sense of depth while keeping parallel lines actually parallel and measurements consistent. |
| Perspective View | A view where parallel lines converge toward a vanishing point, the way human eyes and cameras actually see — realistic-looking, but not directly measurable the way isometric and orthographic views are. |
| Wireframe | A view showing only an object's edges as lines, with no surface fill — useful for seeing through an object to its internal structure. |
A perspective view looks the most "realistic," but its converging lines make it genuinely hard to measure or compare distances accurately. An isometric view sacrifices some of that photographic realism specifically to keep every measurement honest and comparable — exactly why nearly every CAD tool in this book defaults to an isometric-style view for actual modeling work, saving perspective rendering for final presentation images.
Pick a simple object (a shoebox, a mug, a phone). Draw it three ways: as an orthographic front view (flat, no depth shown at all), as an isometric view (using 120° angles, a ruler helps), and as a rough perspective sketch. Compare all three and write 1-2 sentences on what each is actually good for.
Looking ahead: Chapter 2 covers what CAD software is actually doing under the hood, and why the 4 tools in this book represent genuinely different approaches to the same underlying problem.
Chapter Two
02
CAD (Computer-Aided Design) isn't one single technology — it's a family of genuinely different approaches to building a 3D model, and understanding the real differences explains why this book's four tools feel so different from each other.
This chapter covers how 3D models are actually stored and built (solid, mesh, and surface modeling), and the parametric-vs-direct distinction that separates the two professional CAD tools in Chapters 4 and 5.
| Solid Modeling | Represents an object as a genuinely solid volume with defined mass and interior — the standard for engineering/CAD tools, since it always represents something physically manufacturable. |
| Mesh Modeling | Represents an object as a network of connected flat faces (usually triangles or quads) approximating a surface — the standard for 3D art, games, and animation, prioritizing visual flexibility over guaranteed physical accuracy. |
| Surface Modeling | Represents an object as a collection of mathematically precise curved surfaces with no defined interior/thickness — used for complex, flowing shapes (car bodies, product housings) before they're finalized as solids. |
| Polygon Count | How many individual flat faces make up a mesh model — higher counts capture more detail but require more processing power and storage. |
An engineer designing a phone case that needs to be manufactured with exact wall thickness needs solid modeling — the software needs to know, precisely, what's material and what's empty space. A 3D artist sculpting a character's face for an animated film needs mesh modeling — total freedom to push and pull a flexible surface, with no requirement that the result correspond to any physically buildable object. This single distinction is most of why Chapter 6's Blender feels like an entirely different program from Chapters 4-5's Fusion 360 and Onshape, even though all three are technically "3D software."
Sketch a simple object twice: once as a "solid" model (shade the whole interior to show it's a filled volume) and once as a "mesh" model (draw only the visible flat triangular/quad faces on its surface, like a low-poly video game character). Label which approach would be better for 3D printing a real part, and which would be better for an animated character, and explain why in one sentence each.
| Parametric Modeling | Building a model from a history of editable steps and numeric constraints (e.g., "this hole is always centered, always 10mm wide") — changing an early step or constraint automatically updates everything built on top of it. |
| Direct Modeling | Editing a model's geometry directly by pushing, pulling, and adjusting its actual faces and edges, with no underlying history or constraint system tracking how it got that way. |
| Feature Tree / History | The recorded, editable sequence of every step used to build a parametric model, viewable and editable at any point after the fact. |
| Constraint | A rule locking a specific relationship in a model (equal length, parallel, centered, an exact dimension) that parametric modeling enforces automatically as the design changes. |
Imagine a water bottle design where the cap needs to always fit the bottle opening, no matter how the rest of the bottle's shape changes during the design process. In a parametric tool, that relationship is defined once as a constraint and holds automatically through every later revision. In a purely direct-modeling tool, changing the bottle's shape means manually re-checking and re-fixing the cap fit every single time — which is exactly why Fusion 360 and Onshape (Chapters 4-5), both built for real manufacturable products, are parametric tools, while TinkerCAD (Chapter 3, built for simplicity) and Blender (Chapter 6, built for art) are not.
Think of a real object with parts that must always fit together correctly (a phone and its case, a jar and its lid, a key and a lock). Explain in 2-3 sentences why a parametric constraint-based approach would make designing that object's two matching parts easier than a purely direct, freeform approach.
Looking ahead: Chapter 3 starts hands-on work with TinkerCAD, the right first tool for building real 3D-thinking skill before tackling professional parametric software.
Chapter Three
03
TinkerCAD is free, browser-based, and built specifically to teach 3D thinking without getting in the way with a complicated interface — the right place to build real comfort with 3D space before moving to professional tools.
This chapter covers TinkerCAD's core workflow: building with primitive shapes, and combining/subtracting them — the 3D equivalent of the Pathfinder operations from The Vector Path.
| Primitive Shape | A basic pre-built 3D form (box, cylinder, sphere, cone, roof) that serves as a starting building block. |
| Workplane | The flat reference grid new shapes are placed onto, representing the "ground" of the 3D scene. |
| Handle | A small draggable point on a selected shape used to resize it along a specific direction. |
| Solid / Hole | In TinkerCAD specifically, every shape is set to either add material (Solid) or remove material from whatever it overlaps (Hole) — the basis of nearly everything built in this tool. |
A huge share of real TinkerCAD models are built from surprisingly few steps: drop a primitive shape, resize/position it, and set it to either Solid (adds material) or Hole (removes it). A simple pencil holder might just be one cylinder (Solid) with a slightly smaller cylinder (Hole) placed inside it and grouped together — two shapes, one combination, one real object.
Create a free TinkerCAD account. Place a cylinder primitive on the workplane and resize it using its handles to about 40mm wide, 60mm tall. Place a second, slightly narrower and shorter cylinder inside it, set it to Hole, select both, and Group them — you've just built a simple open container.
| Group | Combining multiple selected shapes (solids and holes together) into one single, permanent object. |
| Ungroup | Splitting a grouped object back into its original separate shapes for further editing. |
| Align Tool | Automatically aligns selected shapes to each other (centered, edge-to-edge) along any axis, avoiding imprecise manual dragging. |
| Ruler | A precision tool for placing and measuring shapes at exact positions and distances. |
This is a direct echo of The Vector Path's Pathfinder chapter, just extended into three dimensions: complex objects get built by combining simple primitives with Boolean-style add/subtract logic, rather than sculpting or drawing complex shapes from scratch. The 2D pattern (two circles, one subtracted, makes a crescent) becomes the exact same 3D pattern (two cylinders, one subtracted, makes a tube).
Design a simple nameplate: a flat box (Solid) with your name spelled out using the Text shape (also Solid) raised slightly above it, and one decorative hole shape (a small cylinder set to Hole) cut through one corner. Use the Align tool to center your name text on the box precisely, then Group everything into one final object.
Looking ahead: Chapter 4 moves to professional, parametric CAD in Fusion 360 — the real workflow behind manufacturable product design.
Chapter Four
04
Fusion 360 (now branded Autodesk Fusion) is real, professional, industry-standard CAD software — the same category of tool used to design actual manufactured products, free for students through Autodesk's education program.
This chapter covers the real sketch-then-3D workflow every parametric CAD tool shares: 2D sketches, extrude/revolve, constraints, and assemblies of multiple parts.
| Sketch | A flat, 2D drawing on a chosen plane, made of lines/arcs/circles, that becomes the basis for a 3D feature. |
| Sketch Constraint | A rule applied to a sketch's geometry (parallel, perpendicular, equal, coincident) that keeps its shape correct as dimensions change. |
| Dimension | An exact numeric measurement applied to a sketch (a length, an angle, a radius). |
| Fully Constrained Sketch | A sketch where every line's position and size is completely determined by its constraints and dimensions — shown in a different color, with zero ambiguity about its exact shape. |
An under-constrained sketch can shift unpredictably when a later dimension changes, because the software doesn't have enough rules to know exactly what should stay fixed. Professional CAD workflow treats getting to a fully constrained sketch as a real discipline, not an optional nice-to-have — it's what makes the model trustworthy and predictable through every later edit.
Set up a free student account and start a new design. Create a sketch on the XY plane: draw a rectangle, then apply exact dimensions (e.g., 50mm x 30mm) until the sketch turns fully constrained (check the color change/status bar). Draw a circle inside it and dimension its diameter and center position exactly.
| Extrude | Pushes a flat sketch outward along a straight line to create a 3D solid (a circle extruded becomes a cylinder). |
| Revolve | Spins a flat sketch around an axis to create a 3D solid (a simple curved profile revolved 360° becomes a bottle or a bowl). |
| Fillet | Rounds a sharp edge to a specified radius. |
| Assembly | Multiple separate parts combined and constrained together as one working design, with real joints defining how they move relative to each other. |
Both take a flat 2D sketch and turn it into a real 3D solid, but they add depth in fundamentally different ways: extrude pushes straight through space (good for anything with a consistent cross-section, like a box or a bracket), while revolve spins around an axis (good for anything symmetric around a center line, like a bottle, a wheel, or a bowl). Recognizing which real-world shape calls for which operation is a core CAD skill.
Using your Chapter 4.1 sketch, extrude the rectangle 15mm to create a solid block, then apply a fillet to soften its top edges. In a new sketch, draw a simple cup-shaped profile (half a cross-section) next to a centerline, and use Revolve to turn it into a full 3D cup.
Looking ahead: Chapter 5 covers Onshape — a genuinely different take on the same parametric-CAD idea, built entirely in the browser with real-time collaboration.
Chapter Five
05
Onshape covers the same real, professional parametric-CAD ground as Fusion 360, built entirely differently: 100% browser-based, with real-time multi-user collaboration built into its core.
This chapter covers what makes Onshape distinct: no install, real-time collaboration (the same underlying idea as Figma's from The Experience Path), and full version history.
| Document | Onshape's container for a design, always stored in the cloud, never as a local file. |
| Real-Time Collaboration | Multiple people editing the same document simultaneously, seeing each other's changes live — no "save and send the file" step at all. |
| Version History | A complete, automatic record of every saved state of a document, letting a team return to or branch from any earlier point. |
| Branch | Creating a separate, parallel version of a design to try a risky change without affecting the main version — the same underlying idea as version control in software development. |
This is a direct parallel to The Experience Path's Figma chapter: real-time, browser-based collaboration with no install and no manual file-passing. Onshape brought that same idea to professional CAD specifically because a team of engineers working on one product used to face the exact same "who has the current version" problem designers used to face before tools like Figma existed — and solved it the same way.
Create a free Onshape account and start a new document. Build a simple part using a sketch and an extrude, the same workflow from Chapter 4. Invite a partner to the same document (or open it in two browser tabs) and watch changes appear live as each of you edits.
| Factor | Fusion 360 | Onshape |
|---|---|---|
| Access | Desktop app install required | Fully browser-based, no install |
| Collaboration | File-based sharing | Real-time, simultaneous editing |
| Offline use | Possible with local caching | Requires an internet connection |
| Free tier | Education license (student/educator) | Free tier available for public/hobbyist documents |
A real design team choosing between these tools weighs real factors: does the work need to happen offline sometimes? Does the team need true simultaneous editing, or is file-based sharing fine? Both are genuinely professional-grade parametric CAD tools — the choice comes down to workflow fit, the same kind of decision covered throughout The Career Path's discussion of tool and structure choices.
Looking ahead: Chapter 6 leaves precision engineering behind for a completely different paradigm — Blender's mesh-based, artistic approach to 3D.
Chapter Six
06
Blender is free, open-source, and built for an entirely different purpose than the last two chapters' precision engineering tools: organic, artistic 3D work — characters, environments, animation, and rendering.
This chapter covers Blender's mesh-based modeling approach, and its rendering and animation capabilities that have no real equivalent in Fusion 360 or Onshape.
| Vertex | A single point in 3D space, the most basic building block of a mesh (plural: vertices). |
| Edge | A straight line connecting two vertices. |
| Face | A flat surface bounded by edges (usually a triangle or a quad) — a mesh's visible skin. |
| Edit Mode | Blender's mode for directly selecting and moving individual vertices, edges, or faces to reshape a mesh. |
| Subdivision Surface | A modifier that smooths a low-detail, blocky mesh into a rounder, higher-detail surface without permanently altering the simple underlying shape. |
Where Fusion 360 and Onshape build models from precise sketches and constraints, Blender builds them by directly grabbing and reshaping vertices, edges, and faces — genuinely closer to digital sculpting than engineering drafting. Neither approach is "more advanced" than the other; they're built for different jobs, exactly as Chapter 2 explained.
Download Blender (free) and start a new project. Add a basic cube, enter Edit Mode, and practice selecting individual vertices, edges, and faces (Blender's number keys 1/2/3 switch between these selection modes). Pull one face outward to deform the cube into an irregular shape. Apply a Subdivision Surface modifier and watch the blocky cube smooth into a rounded form.
| Material | The surface properties applied to a mesh — color, roughness, reflectivity, transparency. |
| Render | Blender's process of calculating a final, photorealistic (or stylized) image or video from a 3D scene, lighting, and materials. |
| Keyframe | A saved state of an object's position/rotation/property at a specific point in time — animation is built by setting keyframes at different moments, and Blender automatically fills in the motion between them. |
| Rig | An internal skeleton of connected bones added to a character mesh, allowing it to be posed and animated naturally. |
Fusion 360 and Onshape are built to produce manufacturable, physical parts — neither has real animation or photorealistic rendering as a core purpose. Blender's material, lighting, rendering, and rigging/animation tools exist because its actual target output is very often a still image or a video, not a physical object at all — the same real distinction from Chapter 2's solid-vs-mesh discussion, now showing up in what each tool is even trying to produce.
Apply a simple colored material to your Chapter 6.1 shape. Set two keyframes: one with the object in its starting position/rotation, and a second a few seconds later with it moved and rotated differently. Play the animation and confirm Blender smoothly interpolates between the two keyframes automatically.
Looking ahead: Chapter 7 turns any of these four tools' finished models into a real, physical object — how 3D printing actually works.
Chapter Seven
07
This is the moment every earlier chapter has been building toward — taking a model out of the screen and into your hands, as a real, physical object.
This chapter covers exporting a model correctly, how FDM (the technology this classroom's printers use) actually works, and what genuinely happens between a finished digital file and a finished printed part.
| STL | The most common file format for 3D printing — represents a model's surface as a mesh of triangles, discarding any parametric history/color/material data. |
| 3MF | A newer format that, unlike STL, can also preserve color, material, and some printer-specific settings. |
| Manifold / Watertight | A model with no gaps, holes, or overlapping geometry in its mesh — every edge must connect to exactly two faces, with zero exceptions, or a slicer (Chapter 8) can't reliably process it. |
| Wall Thickness | How thick a model's solid walls are — too thin, and a printed part becomes fragile or fails to print at all. |
A model built with an accidental gap, a duplicate overlapping face, or an edge shared by more than two faces is called non-manifold — it doesn't actually describe a physically possible solid object, even if it looks fine on screen. Every tool in this book has a way to check for this (Fusion 360 and Onshape mostly prevent it by design since they build true solids; Blender and TinkerCAD can both produce non-manifold geometry more easily, especially after heavy editing) — checking before export saves real, frustrating troubleshooting later in the slicer.
Take a model you built earlier in this book. Export it as an STL file. If your tool has a built-in check (Blender's 3D Print Toolbox add-on can check for non-manifold geometry directly), run it and confirm your model is watertight before moving to Chapter 8.
Both of this classroom's printers — the Bambu Lab P1S and the Ender 3 — use FDM (Fused Deposition Modeling), the most common consumer 3D printing technology.
| FDM (Fused Deposition Modeling) | Melts a plastic filament and deposits it layer by layer, each layer fusing to the one below it, building a solid object from the bottom up. |
| Filament | The spool of solid plastic wire that feeds into the printer's extruder to be melted and printed — PLA is the most common, beginner-friendly type. |
| Extruder / Hotend | The part of the printer that melts filament and pushes it out through a small nozzle. |
| Bed | The flat surface a print is built on top of, layer by layer. |
| Layer Height | How thick each individual printed layer is — smaller values mean smoother, more detailed prints that take longer; larger values print faster but show more visible layer lines. |
The Bambu Lab P1S is fully enclosed with an active chamber heater, unlike the Ender 3's open frame. This isn't just about noise or safety (though the enclosure genuinely helps with both) — some filaments (like ABS) need a stable, warm chamber temperature to print reliably without warping, which an open-frame printer like the Ender 3 struggles with. This is a real, practical reason a classroom might have both printer types rather than just one.
Looking ahead: Chapter 8 covers the software layer between a finished STL file and an actual print job — the slicer — specifically for this classroom's own P1S and Ender 3 printers.
Chapter Eight
08
A 3D printer can't read an STL file directly — it needs a translator. That translator is called a slicer, and understanding what it actually does is the last real skill this book teaches.
This chapter covers what slicing software does conceptually, the specific slicers used with this classroom's P1S and Ender 3, and the print settings that matter most.
| Slicer | Software that converts a 3D model into flat, horizontal layers and generates the exact machine instructions (G-code) a printer follows to print it, layer by layer. |
| G-code | The actual, low-level instruction file a slicer produces — the precise, literal path/speed/temperature commands a printer's control board executes. |
| Infill | The internal support structure printed inside an otherwise-hollow part, described as a percentage — 100% would be fully solid, most functional parts use 15-30%. |
| Support Material | Temporary, removable printed structures holding up any part of a model that would otherwise print in mid-air with nothing underneath it. |
The name isn't a metaphor: a slicer mathematically cuts a 3D model into dozens or hundreds of thin horizontal cross-sections (matching the layer height from Chapter 7), then calculates the exact nozzle path needed to trace each one, plus infill and any needed supports, and finally converts all of that into G-code the printer's motors and hotend actually follow, one instruction at a time.
Think of a model with a horizontal overhang (like a "T" shape upside down, or an arm sticking out sideways). Sketch it and mark, in a different color, exactly where support material would need to be added underneath the overhanging section for it to print successfully.
| Printer | Recommended slicer(s) | Notes |
|---|---|---|
| Bambu Lab P1S | Bambu Studio (native) or OrcaSlicer | Bambu Studio is free, built specifically for Bambu printers, and is itself based on the open-source OrcaSlicer — ships with Standard/Sport/Ludicrous speed presets. |
| Ender 3 | Cura, PrusaSlicer, or Creality Print | The Ender 3 is an open, widely-supported printer compatible with essentially every major slicer — a real difference from the more tightly integrated P1S/Bambu Studio pairing. |
Source: Bambu Lab official specifications and slicer documentation, verified 2026-09-09.
The P1S is a tightly integrated system — Bambu Studio knows this exact printer's build volume, speed capabilities, and AMS color-changing hardware in detail, and is built specifically around it. The Ender 3 is an older, open-design printer with a huge, independent community — any major slicer can drive it, but none of them are built exclusively for it the way Bambu Studio is built for Bambu printers. Neither approach is simply better; they reflect two real, different philosophies in the 3D printing industry.
| Print Speed | How fast the printer moves while extruding — the P1S's CoreXY design allows genuinely high speeds (up to 500mm/s) that a standard Ender 3 can't safely match without modification. |
| Print Profile / Preset | A saved bundle of slicer settings (temperature, speed, layer height) tuned for a specific filament and printer combination. |
| AMS (Automatic Material System) | The P1S's optional multi-color/multi-material filament-switching accessory, allowing one print to use several colors or filament types automatically. |
Import your Chapter 7 STL file into Bambu Studio. Choose a Standard speed preset, set infill to 15%, and use the built-in preview to check whether the slicer thinks any part of your model needs supports. If it does, look at exactly where — and compare that to your Chapter 8.1 prediction sketch.
That's the whole book. Eight chapters, from the basic idea of a third dimension all the way to a real, physical object coming off this classroom's own printers. Between this book and the rest of the series, the full arc from a first pencil sketch to a tested digital prototype to an actual physical product is now covered.
Back Matter
This book covers four separate tools plus this classroom's own real printers, so its accuracy rests on each tool's own official documentation rather than a single exam blueprint. This section collects all of them in one place.
| Tinkercad Learn1 | Autodesk's own official learning resources for Tinkercad, the authoritative reference for Chapter 3's interface and workflow facts. |
| Autodesk Fusion Learning | Autodesk's own official tutorials and documentation for Fusion 360, the authoritative reference for Chapter 4. |
| Onshape Learning Center2 | Onshape's own official learning platform, the authoritative reference for Chapter 5's interface and workflow facts. |
| Blender Manual3 | Blender's own official, comprehensive documentation, the authoritative reference for Chapter 6. |
| Bambu Lab Wiki4 | Bambu Lab's own official specifications and Bambu Studio documentation — the source behind Chapter 8's P1S-specific facts (print speeds, AMS, slicer presets), verified September 2026. |
▸ See the Preface at the front of this book for this edition's full license and terms of free use.