Lab 3D

Film an object or a room. Lab 3D makes a 3D model of it on your computer.

Lab 3D is a catalogue of 3D experiments in one window. The Viewer tab opens a 3D scene file in any browser. The other tabs run on engines that Mnemosyne OS installs on your computer, so they open inside Mnemosyne OS only. Outside it, they show Needs Mnemosyne OS.

The cartridge id is @mnemosyne-plugins/lab-3d, under the MIT licence. It replaces the older Objets 3D cartridge.

Open it

Ask the orb or the chat to "open Lab 3D". Once the cartridge is installed, MnemoHub's Launch App opens it in its own window, and Run on Canvas puts it on your canvas.

The tabs

Tab	What it does	Needs Mnemosyne OS
Viewer	Opens a .spz, .ply, .splat or .ksplat scene file	no
Objects	Your 3D objects, and Create an object	yes
Places	Your 3D places, and Create a place	yes
One day	The photos of a day laid inside a place	yes
Decor	An object placed in front of a picture	yes
Paintings	A photo of a painting, in relief	yes
Compare	The same thing filmed at two dates	yes

In every 3D view, drag to turn, use the wheel to zoom and right-drag to move. Turn by itself spins the scene. Reset the view brings back the first framing.

Make a 3D object

1. Open Objects, then Create an object

   The Places tab has the same button, Create a place, for a room or a landscape.

2. Pick the source
   • Video: about 30 seconds, walking around the object. For a place, walk through it slowly.
   • Photos: a folder of photos taken all around. Lab 3D needs at least 20 photos and takes at most 400.
   • Phone: photos taken with a phone and sent over Wi-Fi. See below.
3. Pick the quality and what to keep

   Quick takes about 5 to 15 minutes. Full takes about 20 to 55 minutes.

   Object alone removes the floor and the room. It needs the image engine (Settings › Images) and the background removal model (224 MB). Whole scene keeps everything filmed.

4. Watch the steps

   The steps are Frames, Placement, Turn, Cut-out and 3D object. COLMAP places the frames. Brush builds the object. A live preview appears at Brush's first preview, then sharpens.

   Keep it now stops Brush and keeps the object as shown. Stop throws it away.

When less than a full turn was filmed, Lab 3D says how many degrees it saw. The sides not filmed are guessed. Photos that COLMAP could not place are shown after a failure. They point at the side to take again.

If the graphics card gives up, Lab 3D keeps the object at the last step and offers Make it again on Quick.

Engines it needs

The 3D engine (COLMAP and Brush) and ffmpeg install from Settings › Video. Lab 3D links there when one is missing.

• Linux: object creation is not available yet. COLMAP publishes no Linux build that Mnemosyne OS can install.
• macOS: not available yet. Mnemosyne OS has no Mac build of ffmpeg to install, and the 3D engine also needs macOS 15 or later.
• Windows on x64 is the only system where the whole chain has run.
• Other processors, such as Windows on ARM or an Intel Mac, get no build.

Photos with the phone

The phone and the computer must be on the same Wi-Fi.

1. Choose Phone as the source, then Show the QR code.
2. Scan the code with the phone's camera.
3. The phone warns connection not private. This is expected: the address is signed by your computer. On iPhone, tap Show details, then visit the website. On Android, tap Advanced, then Continue.
4. Take the photos. The counter shows how many reached the computer.
5. Press Done, then Create the 3D object or Create the place.

To skip the warning next time, install Phone's certificate once. It only vouches for your network's private addresses.

When no phone connects, Lab 3D lists three known causes. The phone may be on 4G or on a guest Wi-Fi. Windows may treat the network as public. Or the firewall question about Mnemosyne OS was answered no.

After Done, you choose where the photos go: A vault, a New vault in its own folder, or A folder outside memory.

Places: walk inside

A place opens on the best covered filmed view. Press Walk inside, then drag to look and use WASD or the arrow keys to walk. The keys work by their position, so a French AZERTY keyboard walks with ZQSD. Back to the start returns to the first spot.

Decor

Choose an Object alone, then put a decor behind it.

• Choose a picture uses an image from your disk.
• New decor draws one from a preset (Marble table, Wooden table, Shelf, Photo studio, Garden) or from your own words. Draw costs one picture on your credits. The bill is shown after.
• In relief reads the decor's depth so the room moves as the object turns. It needs the depth model, downloaded in Settings › Images.

Right-drag places the object. The wheel sets its size.

Paintings

Choose a photo of a painting. Lab 3D reads its depth on your computer, for free, and the view drifts slowly inside it. Move the pointer and the view leans toward it.

• Cut out the canvas straightens the canvas alone.
• World of colour masses pushes dark masses back and brings light ones forward.
• Dive into the painting zooms under the pointer. Dive further paints the next level at the centre. Each level is billed on your credits.

Take with the phone sends the photo from a phone, as above.

Compare two dates

Compare needs two objects, or two places, of the same thing filmed on two dates. Pick the two dates on the timeline, then Put them in one frame. The alignment takes about a minute on your computer.

The result is Aligned, Aligned, but poorly or Not aligned. When not aligned, Lab 3D does not lay the two dates on top of each other. Three modes show the change:

• Timeline slides from one date to the other.
• Curtain splits the view at a line you drag.
• Differences colours what changed, from a viewpoint both videos filmed. Hatched areas were not filmed by both.

One day

Arrives in the next build

One day was merged after Mnemosyne OS 2.2.0. It is not in the released app yet.

Film the place empty first, in Places. Then open One day and pick that place.

• Walk to a stand and press Pin a spot here. Name the spot.
• Add photos to a spot from the Phone or a Folder. Each batch becomes a moment. Its time comes from the photo's EXIF data, else from the file.
• Photos with no spot wait under To place.
• The timeline sets the hour. Play the day flies from spot to spot.

A day keeps paths and positions, never a copy of a photo. The photos stay in their folder or phone series. Remove deletes the day and leaves the photos on disk.

Where your data goes

• 3D objects and places are made and stored on your computer, under ~/.mnemosyne/generations/splats.
• Decors and days are kept in the window's storage, with a copy held by Mnemosyne OS.
• Phone photos go to the vault or folder you choose after Done.
• Two actions use your credits: Draw a decor, and Dive further in a painting. Everything else runs locally.