Using Billboards
A billboard is a panel that stands in the 3D scene and carries pictures. It is the way to get something that is not the outcrop into the outcrop: a field photograph of the same bed elsewhere, a core shot, a location map, a panel of text explaining what a visitor is looking at, or a video of a modern analogue playing with its sound.
A board is not limited to one image. Give it several and it becomes a small presentation you page through in place, which is what makes billboards the workhorse of a virtual field trip as well as a way of annotating your own work.
Everything below is written for the Vulkan 3D view, which is where billboards are most complete. The OpenGL view draws the same boards and plays the same video, but drives them differently — the differences are collected in In the OpenGL view.
Placing a board
There are three ways in, and they do different things.
| Route | What it does |
|---|---|
| Annotations tab → Billboard, then click the model | Arms the placement tool. The click opens a file dialog; pick one or more images or clips and you get one board per file, all anchored at the same point. |
| Drag a file from Explorer onto the 3D view | Drops a board at the surface point under the cursor. If the drop misses the model it lands at the point the camera is looking at. |
| Data Tree → right-click a board → Add image | Adds to a board that already exists rather than making a new one. This is how you build a multi-image board. |
The board is anchored 0.5 m above the point you clicked, so a board planted
on a cliff face sits just off the rock rather than inside it. Files you choose
are copied into the project's SLIDES folder — the originals are not
referenced afterwards, so the project stays self-contained.
Media a board can hold
| Kind | Formats |
|---|---|
| Images | .jpg, .bmp, .png, .tif, .tiff |
| Video | .mp4, .avi, .mov, with the audio track |
One board's list can mix stills and clips freely. Whether an entry is a video is decided from its file name, so it survives saving and reloading with no separate setting to get wrong.
One clip plays at a time on a board. Paging onto a video opens it; paging away closes it again and remembers where you had got to, so returning to a clip resumes rather than restarts.
Board size and shape
The board is a fixed mat sized to its widest item, and every item is drawn at full board height, centred. Paging between a portrait photograph and a landscape clip therefore does not make the panel grow and shrink under you — the widest item fills the mat exactly and narrower ones sit on a wider surround.
Working with a board
Click the picture to select the board. That is what puts its header strip and controls on screen; an unselected board is just the image on its mat, which is what you want in a scene full of slides. Click it again to deselect.
Selection is exclusive — bringing one board's controls up puts every other board back to just its picture. Clicking the model or the sky does not deselect; only clicking the board again does, or selecting anything in a tree.
While an interpretation tool is armed, a click passes straight through the board to the rock behind it. That is deliberate: digitising a line across a board has to keep landing on the model. Boards only take the click during plain navigation.
The controls
| Control | Where | What it does |
|---|---|---|
| Previous / Next | Ends of the header strip | Page to the previous or next item. Only shown when the board holds more than one. |
| Play / Stop | Header strip, left | Starts or stops the clip — one button that swaps its icon to show the state. |
| Rewind | Header strip, centre | Back to the start, keeping the current play state: a running clip restarts from the top rather than halting. |
| Repeat | Header strip, right | Loop the clip at the end. Lit and held in while looping is on. |
| Header strip | Above the image | Anywhere a control is not, the strip is the grab handle — drag it to move the whole board. |
| Scrub bar | Below the image | Video only. Click or drag along it to seek; playback pauses for the drag and resumes on release. |
| Resize handle | Bottom-right, just outside the board | Drag to resize. The scale is uniform, so the aspect ratio is preserved. |
The transport controls only appear when the item showing is a video. On a narrow or portrait board every button in the strip shrinks together rather than the transport sliding under the page arrows, so a control is never ambiguous to click.
Moving a board precisely
The header drag moves the board in the plane facing the camera through its current anchor, which keeps it at the same distance from you. For an exact position use either:
- Interpretations tab → Edit → 3D Translate, then click the board — the translate gadget attaches to its anchor and you drag the arms; or
- the Position rows in the property grid, typed directly.
Video in the scene
Video on a board behaves like a small player embedded in the outcrop.
- Audio is the timing master. When a clip has a sound track, the picture is pulled onto the audio clock rather than the other way round, so sound and picture stay together.
- Recorded flight paths capture it correctly. During a flight path recording the clip is driven by the movie's own frame clock rather than the wall clock, so it plays at natural speed in the finished video instead of racing the camera, and frames are decoded synchronously so no captured frame is a stale one.
- Only the clip on show decodes. Paging away from a video stops it.
A 60 fps clip costs roughly twice the decode work of a 30 fps one, and the 3D view has to paint as well. If playback stutters on a laptop, re-encode the clip at 30 fps before blaming the model.
Properties
Select a board — in a tree, or in the 3D view — to get its property page.
| Property | What it does |
|---|---|
| Name | Name of the board, as shown in the Data Tree. |
| Scale Factor | Board height in world units. The width follows from the widest item's aspect ratio. |
| Position | The board's anchor, typed as X / Y / Z. |
| Show Frame | Draw the mat and rim behind the image. (Vulkan view.) |
| Frame Colour | Colour of the rim around the mat. (Vulkan view.) |
| Lock Face On | Keep the board turning to face the camera. Turn it off to glue the board to a fixed bearing. (OpenGL view.) |
| Facing Direction | The bearing the board faces when Lock Face On is off. (OpenGL view.) |
| Show StraboSpots / StraboSpot Size | On a board imported from StraboSpot, draw a pin on the photograph for each spot pinned to it, sized as a fraction of the board height. |
| Rotate Image | A dropdown — 90 clockwise, 180, 90 anticlockwise — that turns the image showing. It rewrites the file on disk, for photographs that arrived with their orientation baked in the wrong way. Stills only. |
Transparency and Visibility Range appear on the page and are saved with the project, but neither renderer reads them — a board always draws fully opaque and at any distance. Lock Face On and Facing Direction are honoured only in the OpenGL view; a Vulkan board always turns to face you, and Facing Direction is not saved with the project in either view. Show Frame and Frame Colour work only in the Vulkan view, and return to their defaults when the project is reloaded.
Organising boards
Billboards live under Billboards in the Data Tree and can be put into folders: select several, then Group on the right-click menu (Ungroup takes them back out). Right-clicking a board there also gives you Look At, which takes the camera to it, plus the usual rename, delete and visibility.
A billboard records the name of the folder it sits in, and the folders are rebuilt from those names when the project opens. A folder with no boards left in it has nothing to record it, so it disappears.
In the OpenGL view
| Behaviour | Vulkan view | OpenGL view |
|---|---|---|
| Controls | Appear when the board is selected, hidden otherwise | Always drawn |
| Move | Drag the header strip, or 3D Translate | 3D Translate only |
| Resize | Drag the corner handle | Hover the board and Ctrl + wheel |
| Seek a video | Click or drag the scrub bar | Click the progress bar (no drag) |
| Video transport | Play / Stop, Rewind, Repeat | Play / Stop and Repeat; no Rewind |
| Page a video board | Previous / Next work while a clip is showing | The arrows are drawn but do not respond while a clip is showing — page off it from the Data Tree instead |
| Frame / Frame Colour | Honoured | Ignored; a fixed dark mat and blue header are always drawn |
| Lock Face On / Facing Direction | Ignored — always camera-facing | Honoured |
| Drop a file onto an existing board | Always makes a new board | Adds the image to the board under the cursor |
Where the files live
| Content | Location |
|---|---|
| Source images and clips | SLIDES in the project folder |
| Display-ready image bakes | BILLBOARDS in the project folder, one .vbbtex file per board |
The bakes are a cache, loaded a slide at a time as you page, which is why a twenty-slide board opens as quickly as a one-slide board. A project backup zips the database, not the project folder, so the bakes do not travel with a backup — they are rebuilt from the source images on first display. Save As copies the whole folder, so a copied project keeps everything.
Troubleshooting
The board is there but the picture is blank.
The source file has gone from SLIDES, or the clip will not open. Check the
board's image rows in the Data Tree against the contents of the folder.
Clicking the board does nothing. An interpretation tool is armed, so the click is going through to the model. Reset to the navigation tool first.
The controls will not appear. The board is not selected. Click the picture itself, not the mat around it.
See also
- Billboards context menus — the Data Tree commands in full.
- Adding billboards — the quick-tip video.
- Building and Delivering a Virtual Field Trip — where billboards earn their keep.
- Flight Path User Guide — presentation slides on a guided tour, which use the same board.