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Assignment Specs & Lab Rubrics
Topology Fix Challenge

Topology Fix Challenge

topology-fix-challenge 90 min
Standards (3)
  • GD.17.4 Art & Design Fundamentals
    Apply elements and principles of art and design to develop game environments, characters, and props for use in interactive 3D games.[^12]
  • 4.3 Industry-Standard Technology
    Use industry-standard hardware, software, and technology to complete tasks accurately, efficiently, and safely.
  • AV.17.8 3D Animation Fundamentals
    Design and model props, vehicles, and characters to demonstrate core animation principles (e.g., weight, timing, visual storytelling); develop and apply rigging systems to enable animation using keyframing and/or match moving.[^10]

The task

You’ll be given a 3D mesh that’s deliberately broken: a combination of non-manifold edges, open boundary holes, internal faces, n-gons, a badly placed pole, doubled vertices, and flipped normals. Find every problem, fix it, and prove the mesh is clean.

This is a diagnostic exercise. The value is in finding problems you didn’t create, which is a different skill than avoiding them in your own work, and it’s the skill that will let you rescue a downloaded or teammate-built asset later this year.

Before you start

Read Topology and Edge Flow (BLND-201).

Starter Script Download: Download the generator script generate_topology_challenge_file.py to generate your exercise asset inside Blender.

Steps

Step 1 — Run the generator script

  1. Open Blender: File > New > General.
  2. Switch to the Scripting workspace (tab along top header).
  3. In the Text Editor panel, click Open and select generate_topology_challenge_file.py (or click New and paste the code in).
  4. Click the Run Script button (play icon).
  5. Switch to the Modeling or Layout workspace. You will see a sci-fi pedestal console named Broken_Console_Prop.
  6. Immediately save your file as LASTNAME_TopologyChallenge_v01.blend in your 01_Projects directory.

Caution

Look at it first. Do not fix anything yet. Before-and-after proof is required for your portfolio write-up.

Step 2 — Diagnose before touching anything

Take diagnostic screenshots while the mesh is still broken:

  1. Shaded View: Take a screenshot of the mesh from an angle showing the visible shading pinch or faceted distortion.
  2. Non-Manifold Check: Tab into Edit Mode (Tab), ensure nothing is selected (Alt + A), then choose Select → All by Trait → Non-Manifold. Take a screenshot showing the highlighted orange edges and open boundaries.
  3. Face Orientation Check: Open the Viewport Overlays dropdown and check Face Orientation. Take a screenshot showing any inverted red faces against the blue mesh.

Step 3 — List what you found

Before fixing anything, write a numbered list in your notes:

  • How many separate problem areas did you identify?
  • What type is each flaw? (e.g., Non-manifold edge shared by 3 faces, unsealed boundary hole, loose floating vertex/edge, 6-sided n-gon, 5-edge pole, inverted face normal, coincident doubled vertices).

You will use this checklist to verify your repairs at the end.

Step 4 — Fix the non-manifold geometry

Work through the structural flaws first:

  1. Delete Loose: In Edit Mode, select all (A), go to Mesh → Clean Up → Delete Loose to purge stray unattached vertices and floating wire edges.
  2. Merge by Distance: Press M → By Distance to weld overlapping vertices sitting at the same coordinates. Notice the status message at the bottom confirming how many duplicate vertices were removed.
  3. Remove Internal Faces: If an internal face is trapped inside, switch to Face select (3), select the internal face, and press X → Faces.
  4. Seal Open Holes: Select the boundary loop around the open side hole (Alt + click the rim edge) and press F to fill, or use Face → Grid Fill for clean quad subdivisions.

Check your work: Re-run Select → All by Trait → Non-Manifold. The selection should be significantly reduced or completely clear.

Step 5 — Fix n-gons and problem poles

  1. Resolve N-Gons: Find the 6-sided n-gon on the angled console face. Use the Knife tool (K) or select opposite vertices and press J (Join Vertices) to split the n-gon into clean four-sided quads.
  2. Reroute Problem Poles: Inspect the front bumper where 5 edges converge into a pole. Use loop cuts or edge rotation to redirect the edge flow so the pole does not sit directly on a visible bend or high-specular curve.

Step 6 — Fix normals

  1. Keep the Face Orientation overlay active.
  2. Select all faces (A) and press Shift + N (Mesh → Normals → Recalculate Outside).
  3. Confirm that every exterior surface of the model is solid blue. No red or pink faces should be visible anywhere.

Step 7 — Confirm it’s clean

Run your final verification tests:

  1. Deselect everything (Alt + A).
  2. Run Select → All by Trait → Non-Manifold.
  3. Blender should select zero edges. Take a screenshot of your 3D viewport showing that nothing lights up. This is your deliverable proof of a watertight, manifold asset.
  4. Temporarily add a Subdivision Surface modifier (Ctrl + 2). Orbit around and verify that the surface smooths cleanly without ugly pinching, creases, or black shading tears.

Step 8 — Write it up

Create a post on your Google Sites portfolio Coursework page with:

  • Your “before” screenshots (showing non-manifold highlights and red flipped normals).
  • Your diagnostic checklist of flaws identified.
  • Your “after” screenshots (showing all blue face orientation, clean wireframe quad flow, and the empty Select Non-Manifold confirmation).
  • A 2–3 sentence reflection: Which topology flaw was hardest to spot, and what tool revealed it?

Submit

Google Classroom Submission: Post the direct link to your published Google Sites portfolio Coursework page in Google Classroom. Keep your repaired .blend file saved in your 01_Projects directory.

Rubric

Assessment Rubric

CriteriaProficient (4-5 pts)Developing (2-3 pts)Beginning (0-1 pt)
Diagnosis & DocumentationThorough before-and-after documentation; accurate inventory checklist identifying all planted flaws prior to repair.Partial documentation; missed 1 or 2 flaws in the diagnostic list or missing initial screenshots.Incomplete documentation; no before screenshots or diagnostic list.
Non-Manifold RepairAll non-manifold edges, T-junctions, unsealed boundary holes, doubled vertices, and loose elements completely fixed. Final Select Non-Manifold selects 0 edges.Most non-manifold issues resolved, but 1 boundary hole or doubled vertex remains.Mesh remains non-manifold with multiple broken edges or holes.
Quad Topology & Edge FlowAll n-gons resolved into quad-dominant topology; problem poles rerouted away from prominent curvature; mesh subdivides cleanly without pinching.N-gons converted with haphazard triangles; minor pinching visible under subdivision.N-gons left unaddressed; severe shading artifacts and pinched geometry under subdivision.
Normal Consistency100% of face normals recalculated outside; verified entirely blue in Face Orientation overlay with zero flipped faces.Most faces oriented correctly, but an interior or recessed face remains inverted red.Inverted normals remain unfixed; shading appears reversed or inside-out.
Portfolio PresentationWell-organized portfolio post with clear headings, labeled comparison screenshots, and insightful reflection on diagnostic tools.Portfolio post contains images but lacks descriptive labels or reflection write-up.Not submitted to Google Sites portfolio.

Notes

  • Screenshot before you fix anything. A repaired mesh proves you can fix problems. Before-and-after proves you can find them, which is the actual point of this assignment.
  • This mesh could be someone else’s work. In GAD2 you will receive assets other students built, and in the game industry you will receive assets outsourced or created by teammates. This diagnostic exercise is a rehearsal for real studio pipeline QA, not a punishment for mistakes.
Thumbnail Ideation SprintTyping & Shortcut Baseline