Capture

Camera settings, running a capture, and what happens when it stops.

Capture drives an orthographic camera along the path and saves one image per shot. The images are stored in your browser as the run goes.

New capture

Opening Capture from a path shows New capture: the path's live settings. Change anything and it is saved into the path. The 3D view shows the shot under the slider, so you can check framing along the whole path before taking a single image.

Pressing Start capture gives the capture a number and freezes the path revision and the settings it started with.

Settings

The settings column has four groups.

Camera, Frame & Grid

Under the form, a line gives the result, for example "50 shots · 2 rows × ~25 columns · 1.24 km".

Unrolling along the road

With unroll along road on, every point beside the road belongs to the place on the road nearest to it, and to the side of the road it is on. Each shot draws only what belongs to its own stretch of road, on the side it photographs, so the far side of a loop, the next turn of a spiral or the other pass of a road that crosses itself never shows in it. The shot is drawn straight into the road's own coordinates: across the frame by distance along the road, up by height, and where two things overlap the one nearer the road in front. That is what a slit looking straight out from every point of the road would see, so the picture does not depend on where the camera stood or which way it faced; the camera only decides which tiles load. Neighbouring frames show the same pixels where they meet, however sharply the road turns. The print's x is the distance along the road on both sides, so a print of the left side and one of the right are exactly as long as the road and line up across it.

• Shots stand a shot spacing apart, and closer only where the road turns so sharply that neighbours would face more than 30° apart. Each faces straight out from the road, so the tiles it loads are the ones its stretch shows.
• A loop gets no second shot where it closes, and its print starts and ends where the loop does.
• On a straight street nothing changes. Round a bend, facades on the inside are stretched a little and those on the outside squeezed, because their length differs from the road's beside them.
• At a crossing, a block on the corner is split along the diagonal: each face goes to the pass along the street it faces.
• A path that passes the same buildings more than once, twice round a block or back along a street it already took, shows each building once, on the pass nearest to it, and leaves gaps on the other. The settings then say how much of the path comes back within 40 m of itself. With each pass separately on, a point belongs to the nearest place on each shot's own pass instead, so every pass shows what is beside it, as a camera on that pass would see it.
• Clip to blocks decides what is drawn, not how much loads. On, only the path's blocks are drawn and each shot's near and far planes are fitted to the blocks it shows. Off, the street, a park and whatever else is beside the road are drawn too, and near (m) and far (m) decide which tiles each shot loads. On a street lined with buildings the two look much alike and load about as many tiles.

Captures taken before unrolling existed, and captures with it off, stitch as they always have.

Without unrolling

Where the street bends toward the camera's side, the edge of a shot swings round and a block there can come nearer than near (m). The part nearer is left out: its walls facing the camera, so the block shows as a hollow shell. A warning under the near and far fields names those shots ("The near plane cuts blocks in shots 7 and 62 (and the rows above); they show hollow."), and its button, set near to -62 m for example, moves the near plane behind the camera just far enough to keep them whole. It is offered only with Clip to blocks on: without it, a near plane behind the camera would bring in your own side of the street. The near plane is never moved for you, because of that trade. A capture already taken keeps its planes: start a new one to move them.

The first and last shot of a row face the same way as the shot beside them, even where the street's line ends in a short turn, such as a slip road into an avenue.

Geometry

• Clip to blocks draws only what lies inside the path's blocks.
• Only photographed side narrows that further to the side the camera faces. It decides one side for the whole path, so it is switched off while unroll along road is on: unrolling already keeps every point to the side of the road it faces there, which also works on a path that loops round more than once.

Output

• Capture width (px): the width of each saved image. The height follows from the aspect.
• Transparent background, or a Background color.

Advanced Timing

How long to wait for tiles (Tile timeout (ms)), how long the view must stay quiet before a shot is taken (Settle quiet (ms)), and a pause before each shot (Capture delay (ms)). The defaults suit most connections.

While it runs

• The settings are read-only.
• Progress is shown above the 3D view, in the path column and in the strip at the bottom of the window.
• The window has to stay visible and in front. When it is not, the capture pauses ("Paused — return to this window to resume") and continues by itself when you come back.
• Stop capture ends the run. The images saved so far are kept.

Afterwards

A shot that could not load its tiles in time is marked for retry and taken again when you resume.

Each frame is also checked for clipping as it is taken. If something in a frame of the highest row reaches the frame's top edge, the top of a building may go on above it; if something in a frame of the lowest row reaches the bottom edge, its foot may go on below it. Under the shot slider a warning then says "You might be clipping the top" or "You might be clipping the bottom", how many frames it is and which shots, and the frames are marked on the slider, above it for the top and below it for the bottom. The frames are kept and the warning stays; raise top alt (m) or lower bottom alt (m) and capture again to take in what was cut off. Opening the capture later shows the same warning. A bottom edge more than 3 m below the street, found from the tiles under the shot, does not count: what reaches it there is the street's underside seen edge-on, not a facade cut off.

Opening an older capture

Captures are listed in the path column and in the Library. Opening one shows it as it was: its own settings and geometry, read-only. If the path has changed since, the column says so ("This capture is frozen at rev 2; the path is now rev 3."). New capture from rev N goes back to the live settings.

Plan JSON, in the bar above the picture, saves the capture plan the capture was taken with: its camera settings, every shot's place and heading, and the clip. Library › Import… takes it back, to take the same shots again.

When a capture cannot start

• Settings not saved. A change is still being written, or could not be.
• Capture blocked. Only photographed side could not be applied safely to this path. The message offers Turn off Only photographed side.
• No shots. The camera settings produce none for this path.