HALL
MONITOR.

1. Play the finished demo. List what the droid does to the real hallway: where its light lands, where it reflects.
2. Scrub the plate. The camera flies forward and drifts right. Which things stay sharp and still enough to follow? (Corners, signs, door frames, light fittings.)
3. Which things would be bad to follow? (Reflections on the polished floor: they slide as the camera moves.)
4. Look at the floor. Where is it shiny and where is it dull? That decides where a reflection can show.
5. Write a three-line plan: what you track, what you build, what you composite.

1. Open the Motion Tracking workspace. Open the first image of the plate; Blender loads the whole sequence. Click Set Scene Frames.
2. Go to frame 1. In the Track tab click Detect Features. Raise or lower Threshold in the pop-up until you get 40 to 60 markers spread over the whole frame.
3. Click Track Forwards (the arrow buttons under Tracking Settings). Wait until it reaches the end.
4. Go to the middle of the shot and to the last frame. Detect Features again on each, then track backwards and forwards. New parts of the hall come into view, so they need their own markers.
5. Play it back. Delete any marker that slides along a reflection or jumps (select it, press X).

1. In the Track panel on the right, set the camera’s Focal Length to 26.3 mm and Sensor Width to 36 mm. This is the drone’s lens.
2. Solve tab: set Keyframe A to 1 and Keyframe B to 270. Leave Refine › Focal Length off. Click Solve Camera Motion.
3. Read the Solve error at the top of the editor. A first try is often 5 to 10 pixels. That is normal.
4. Open Clean Up. Set Error to 3, Action to Delete Track, and click Clean Tracks. Solve again. Repeat with Error 2, then 1.2.
5. Stop when the error is under 1 pixel and you still have at least 100 tracks. Then click Set as Background and Setup Tracking Scene.

1. Press Numpad 0. You see the plate with small dots: the solved points. Dots on the floor show where the floor is.
2. Add › Mesh › Plane. Scale it long and narrow and move it until it lies through the floor dots for the whole shot. Scrub to check it does not slide.
3. Duplicate it and stand it up for the left wall and the right wall, through the dots on the lockers and the blue wall.
4. Add an end wall at the far door and a ceiling through the light fittings.
5. Give all five a plain white material with Roughness 1. They will never be seen; they only catch light and shadow.

Click by click (real Blender screenshots)

1. Sketch it first: a body, one feature that shows which way it faces (an eye, a lens, a nose), and something that explains how it flies or senses.
2. Add › Empty and name it Droid. Build every part as a child of it, so the whole machine moves as one.
3. Body: a UV Sphere, shaded smooth. Add a ring (Torus), an eye (a small sphere in a short cylinder), fins or an antenna.
4. Size it from the scene: the hall is about 2.7 m wide, so a droid 40 cm across is roughly one seventh of the width.
5. Materials: one light metal, one dark trim, and an Emission material for the eye.

1. Plan three beats: it travels, it notices something, it leaves. Write the frame number for each.
2. Frame 1: place the droid ahead of the camera at head height. Press I and key Location and Rotation.
3. Every 40 to 60 frames, move it further down the hall and a little side to side, and key again. Keep it in front of the camera: it should look as if the camera follows it.
4. The notice beat: over about 20 frames, stop it and turn it 180° to face the camera. Hold for a second. Turn it back and send it off faster.
5. Play it. Fix anything that looks like sliding on ice by adding a keyframe in between.

1. Add › Light › Spot. Parent it to the Droid Empty, place it at the eye, and tilt it to point ahead and down at the floor.
2. Pick a strong colour. Set Spot Size to about 50° and Blend to about 0.35 for a soft-edged pool.
3. Raise Power until, in Rendered view, a clear pool of colour lands on the white floor stand-in ahead of the droid.
4. Key the light’s rotation every 20 frames or so, so it sweeps a little from side to side.
5. When the droid looks at the camera, key two short pulses of extra Power.

1. Droid: hide the stand-ins from the render (camera icon in the Outliner). Tick Film › Transparent. Render to a folder called droid.
2. Lit, no droid: show the stand-ins, hide the droid and switch the scanner off. Untick Transparent. Render to shadow_a.
3. Lit, droid casting: show the droid again but untick Object properties › Visibility › Camera on its parts, so it casts a shadow without being seen. Render to shadow_b.
4. Scanner only: switch the room lights and World off and the scanner on, with the droid hidden. Render to light.
5. Check one frame of each before you render 270.

1. Add the plate and your four passes as Image nodes (sequences of 270 frames).
2. Shadow: Blur both shadow passes a little, then Mix › Divide (A = shadow_b, B = shadow_a). The result is white everywhere except the shadow. Multiply the plate by it.
3. Light: Mix › Multiply the plate by the light pass, then Mix › Add that onto the plate. The real floor now carries the scanner’s colour.
4. Droid: Alpha Over, Background = the result so far, Foreground = the droid pass.
5. Finish with a Glare node set to Bloom with a high Threshold, so only the eye glows. Play the whole shot.

Click by click (real Blender screenshots)

1. Read your director’s card (below).
2. Decide which stage it touches: track, stand-ins, droid, animation, light or composite. Change as little as possible, in a copy of your file.
3. Re-render only the passes the change affects, and render the shot (FFmpeg, H.264).
4. Screen it and explain one tracking choice and one compositing choice.
5. Credit the footage and anything you did not make.

Independent evidence: the main achievement evidence for this tutorial.