Week 03 · Blockout & true scale — FMX 430 Spatial Computing

By the end of this session you can

Convert real-world measurements into Unreal units (1 uu = 1 cm) without a single "looks about right."
Greybox an architectural space with modeling tools, snapped to a grid that matches your measurements.
Use a mannequin and play-in-editor eye height to verify scale against the real space.
Direct an AI agent to block out geometry from a measurement list — and check its math.

2:00 · Brief The tape measure is the tool

Everyone in this room has stood in a virtual space that felt subtly wrong — ceilings too grand, chairs slightly toylike. That wrongness is almost always scale, and your body detects it in milliseconds even when your eyes can't say why. Project 1 exists to train that judgment out of guesswork and into measurement.

Greyboxing: designing before decorating

A blockout (greybox) is the space with everything removed except the decisions that matter: proportions, openings, sightlines, circulation. Grey boxes, no materials, no props. The discipline is refusing detail until the bones are right — because moving a wall costs nothing in a greybox and everything in a dressed scene. Professional level design lives and dies in this phase; so will your Project 1 grade.

1:1 or nothing

Unreal's convention: one unreal unit is one centimeter. A 2.4 m ceiling is 240 units, full stop. The numbers that anchor a human-scale space: door openings around 80–90 cm wide and roughly 205 cm tall, counters near 90 cm, seat heights near 45 cm, eye height around 160–170 cm. When you rebuild your measured room, every one of these comes from your tape measure, not from this list — the list just tells you which numbers to go collect.

Reference is evidence

Project 1's brief (see the Projects tab) requires a reference sheet: photos plus measurements of the real space. Treat it like a surveyor would — a floor-plan sketch with dimensions written on it, photos from repeatable positions, heights as well as widths. The test at crit in Week 6: someone who knows the real space should feel its proportions in the headset.

State of the Art · Living in the model

Architecture has moved from showing a model to walking inside it at 1:1 — and manufacturing (BMW, Boeing, Siemens) mirrors entire factory floors as digital twins. The scale discipline you're practicing this week is the exact skill those sectors hire for. Discussion: what breaks — trust, safety, sales — when the virtual twin doesn't match the tape measure?

Digital twins & spatial computing (2025)

2:45 · Guided lab Measure, then build

We greybox a shared reference space together — a corner of CCB-134 itself, measured live — so everyone leaves knowing the workflow before applying it to their own Project 1 space.

Measure for real
In pairs, measure the room's key dimensions with a tape: wall lengths, ceiling height, the door opening (width and height), one window. Sketch a plan and write every number on it. Photograph the sketch — it goes in your reference sheet.
A level for the blockout
New Basic level in your sandbox, saved as L_Blockout_Cass. Delete the default floor if it fights your plan; your measured floor replaces it.
Set your snapping to match reality
Set grid snapping to 10 (10 cm) in the viewport snapping controls — fine enough for architecture, coarse enough to stay aligned. All translation happens snapped today.
Block the shell with modeling tools
Switch to Modeling mode from the mode selector in the main toolbar. Create boxes for floor and walls, typing exact dimensions rather than dragging by eye — a 412 cm wall is 412 units, not "about four meters."
Cut the openings
Build door and window openings at their measured sizes — as gaps between wall segments or with the modeling tools' boolean operations, whichever you can control precisely. The door opening is the scale anchor your body knows best; get it exact.
Place the mannequin
Add a human-scale reference — the UE mannequin (from the Third Person content, added via the Content Browser's Add menu) or any 180 cm reference figure — and stand it in the doorway. If the mannequin looks wrong in the door, one of your numbers is wrong. Find which.
Walk it
Play in editor and walk the space. Compare what your eyes report against the room you're physically sitting in. Note every spot where the virtual room feels off, then check those measurements first.
Commit the greybox
git add -A && git commit -m "Week 3: measured blockout". Push before the AI lab.

4:00 · AI lab The agent takes measurements

Now the same job, delegated: feed Claude Code your measurement list and have it block out the space through the MCP server. The agent is fast at geometry and indifferent to whether the geometry is true — the tape measure stays in your hands.

Prompt 1 · Blockout from a spec

Here are the measurements of a real room, in centimeters: [paste your measured list — wall lengths, ceiling height, door and window openings with positions]. In a new outliner folder called AI_Blockout, block out this room at 1:1 scale using box geometry. 1 unreal unit = 1 cm. Leave the openings as gaps.

Give it your real numbers, not the class demo's. Then audit like a building inspector: select the agent's walls and verify dimensions in the Details panel against your sketch. Agents happily transpose digits and confuse meters with centimeters — that's the lesson.

Prompt 2 · Scale audit with a mannequin

Place a human-scale mannequin actor in the doorway of the blockout you just built. Then list every dimension in the room that seems inconsistent with human scale and tell me your reasoning.

Interesting either way: if the agent flags real problems, it caught your measuring errors; if it invents problems, you've caught its confidence outrunning its evidence. Cross-check each claim before believing it, and log the score.

Prompt 3 · Compare builds

Compare the room in the AI_Blockout folder with the one I built by hand in this level. List every dimensional difference between them.

Two blockouts of the same room from the same numbers should be identical. Where they differ, one of you made an error — determining which is exactly the verification habit this course is about.

Before you call it done

Your hand-built blockout matches your measurement sheet — spot-check at least five dimensions in the Details panel.
The mannequin reads correctly in the doorway of both blockouts.
You found and explained at least one discrepancy in the agent's build (or proved there were none).
Your Project 1 space is chosen and its reference sheet started.
AILOG.md entry #3 written; repo committed and pushed.

5:15 · Crit / share Choose your room

Everyone declares their Project 1 space with photos and rough dimensions, and takes thirty seconds to defend the choice: what makes its proportions worth rebuilding? A good Project 1 space has a scale signature — something a body would recognize. We pressure-test the risky picks now, not at crit.

Homework — due before Week 4

Task	Deliverable
Fully measure your Project 1 space: plan sketch, all heights and openings, photos from repeatable positions.	Complete reference sheet committed to your Project 1 repo.
Blockout your space at 1:1, hand-verified with the mannequin and a PIE walkthrough.	Greybox level in the repo — grey boxes only, no materials, no props.
Log the week's AI sessions, including the discrepancy audit.	`AILOG.md` entry with your agent-vs-hand comparison results.

Resources

Epic Developer Community — Learning — the level-design and modeling-mode guided courses cover today's toolkit.
Unreal MCP docs — reference for the actor and geometry toolsets the agent used today.
Digital twins & spatial computing (2025) — this week's State of the Art reading.
Project 1 brief — deliverables and assessment criteria for the Realistic Virtual Environment.