# Modeling & Photomatching :::tip Download the project files The .blend base file and the reference images used in this walkthrough. [Download Project Files](#) ::: ## Introduction This is the second half of the worked reconstruction: with the camera matched, you model the building against it. The camera is not a backdrop here, it is the measuring instrument. Every shape gets checked by looking through it. It is also an introduction to applying Blender's edit mode. The tools arrive when the building needs them — extrude, edge slide, loop cut, bevel, knife, symmetry — instead of as a list of what each one does. You learn them on a structure that has to be right, on a real case rather than a random cube. The walkthrough runs 55 minutes. Work it beside the video; come back to a single section when you need it. ## How to Break Down a Building The walkthrough starts before any modeling, with a question: what is this building, really? In essence it is a combination of squares and cubes with some shared surfaces and aesthetic details. Break it into layers. The first layer is the silhouette — the rectangular volumes of the main body, the protruding section, the roof structure. The second is doors and windows: they verify your proportions, give the facade structure, and later act as guidelines when you match other photos. Ornament and trim are a third layer, and they are not your priority: they add nothing to what this model must do. The goal is a lean, flexible blockout — simple enough to edit — so that each matched photo can refine dimensions and fill in what the sources do not show. The video also states its teaching rule up front. Most edit-mode videos explain what a tool does, which hands you a solution to a problem you do not have. Here you know what you want to build, and each tool appears when the build needs it. ## Edit Mode Essentials Clean the scene first: name the camera and the blockout mesh, move things into collections, hide the satellite imagery. Then select the blockout and enter edit mode — from the dropdown at the top left, or with Tab, which toggles between object mode and edit mode. If that distinction is new to you, [Foundation's Object Mode page](../../foundation/04-blender/object-mode.md) sets it up and hands over here. The toolbar changes, and it holds fewer tools than you expect. They are ordered by importance: extrude sits at number one because you use it constantly. Each tool has its own page in the knowledge base; this walkthrough covers them as it needs them. Switch what you select with 1, 2 and 3: vertex, edge, face — or hold Shift to combine modes. The active mode shows in the top-left corner, and it is the first thing to check when something refuses to select. Transforms behave as in object mode but act on your selection: G, R, S, axis locks, Ctrl to snap to vertices, Shift for finer moves. ## The Blockout Work top down — there is no visible ground floor to work bottom up from. Everything from here falls into three categories: you transform geometry, you add to it, or you take it away. Start from the roof edge. Select the edge, press E to extrude, lock it to Z, then move the result along Y until the roof line matches the photo. When a face must slide along its own angle instead of free-moving, press G twice: the edge slides within the borders of the face it belongs to, clamped to that face. Place a loop cut with Ctrl+R before you extrude a stretch, so the new geometry stays attached and the loops run clean around the mesh. Press Ctrl+R again at any time to check that a loop still travels where you expect. ## Viewport Aids and Selection As depth accumulates, the mesh gets harder to read, and the viewport offers help. X-ray (Alt+Z) lets you see and select through the geometry in front; adjust its level until the wireframe reads clearly. Backface culling and cavity shading separate faces from each other. Two operations remove material. Delete leaves holes where the faces were. Dissolve takes the selection away and lets the surrounding geometry close over it. Choose deliberately. Then the selection tour — the video admits it is a detour, because selecting what you want is the cornerstone of your flow. Click selects, Shift adds, click again removes. Alt+click an edge for its loop. Ctrl picks the shortest path between two selections. Ctrl+plus grows, Ctrl+minus shrinks. Select Similar matches by material or by normal. Press L to select a linked island: one object can hold several loose parts, which matters when windows arrive. And in Properties to Data, a vertex group stores an intricate selection so you can recall it later. ## Symmetry, the Balcony and the Gutter Symmetry lets you place geometry once. Set the loop cuts on one side, mirror them, and both flanks stay identical — which is what you want when the next camera match will check both. The balcony is blocked in with the same logic: loops first, then the volume. The gutter tests your sequencing. It was noticed during the blockout and deliberately deferred — model it later, once the facade around it exists. That is a habit worth copying: add detail when the structure below it is stable, not before, and keep the mesh clean as you go. ## Join, Knife and the Dome Two more ways to cut geometry. Join (J) connects what you select: two vertices joined become an edge that splits the quad between them. The knife tool (K) cuts freehand — hold Shift to snap to an edge's midpoint, right-click to start a new cut, Space to apply. Press S for measure mode, with dimensions and angles as you cut, and A to lock an angle — an angle is relative to the view, so work in front view for a true 90 degrees. C cuts through the whole object. The dome starts from a saved outline: duplicate the crown faces with Shift+D, move them up, and extrude the edges until the profile closes. Leave it disconnected from the house for now — joining it would drag loop cuts through its topology — and use L to select and work each island separately. When a pass ends, select all and merge by distance: no vertices removed means the mesh is clean. ## Windows and Doors The loop cuts are already in place from the blockout, so openings become a choice of two tools. Offset Edge Loop Slide — the loop-cut tool's secondary function, behind the gray arrow that marks a tool with more than one mode — slides outward and adds two cuts parallel to the one you pick. Or select the loop cut and press Ctrl+B: beveling the cut gives the same two lines without leaving the original cut in the middle. Bevel normally rounds a corner; here it twins a line. Match the cut positions to what the photo shows — a wider door gets wider loops, a door you cannot see gets none — then select the faces between them and press X to delete. Holes are enough. Window detail is not needed to match the next camera. ## Matching Additional Cameras Matching more cameras repeats setup you already know: add a camera, load the image, set it as a front background. Then choose a route — manual with the Dolly Zoom add-on, Perspective Plotter, or a hybrid: plot first for a starting point, then refine by hand. One-way street: once you match manually you cannot go back into Perspective Plotter, because it updates the camera and cannot take over values you set by hand. Four habits keep it sane. Lock the model's location: it is the reference now, so you match the photo to the model, never the model to the photo. Split the screen and keep a top-down view beside the camera view. Name every camera by how it was matched and what it shows — PP for Perspective Plotter, MM for manual, PH for photo, SV for street view, plus the angle — and turn on Show Name in the object's viewport display so the names stay visible. The live match in the video uses the cross-section at the tower top as its reference length: 856 cm, the same number as the first page. Target location to manual, opacity down, move the camera up. Rough first; refinement comes next. ## The Iterative Refinement Process The rest of the game is adjustment: height, Y position, X position, perspective lines, again and again. The video skips the half hour of it and shows the pattern instead. Each new photo verifies dimensions you had to estimate, catches proportion mistakes, and fills blind spots from another angle — roughly 70% confidence with one photo, 85% with two, closer with three. A misplaced door edge shows the loop in miniature. Grab the edge and move it, or do it properly: re-select with symmetry, walk the shortest path, cut the block in the middle, Ctrl+B, join with J — and then let the next camera match confirm that the change holds up. The closing advice: start with the silhouette, verify with camera matches, improve progressively. This is not about perfection on the first try. It is a flexible blockout that every matched photo refines. ## Summary A model earns trust by being checked, not by being finished. This pass gives you a lean blockout whose proportions survive every camera you match against it, and it gives you edit mode learned where a mistake has consequences. What it does not give you is a finished building. Detail comes later, one verified photograph at a time — and each new angle fills a gap while testing the geometry you already built.
#### Resources - [The Camera Match](./the-camera-match.md) — the first half of this walkthrough - [Geometric Reconstruction](../../../techniques/geometric-reconstruction.md) — the wider playbook - [Scene Management](../../../techniques/6-utility-workflows/scene-management.md) — keeping a complex scene organised - [Scale Estimation & Source Reliability](../../../techniques/1-foundation-preparation/scale-estimation.md) — keeping the dimensions defensible - [Course Syllabus](../syllabus.md) — full course overview and module map
#### Sources 1. [fSpy](https://fspy.io/) — open-source camera matching from vanishing points