Exporting Mask
A fixture mask is an image where the positions of all fixtures and splines of the project are marked in white — exactly as they are arranged in the Mapping window — while everything else remains transparent. Light Stream can save such a mask to a *.png file so it can be used in other programs.
What the mask is for
The mask is a pixel "map" of your object. It is most often used as follows:
- as a base for preparing content in a third-party editor (After Effects, Photoshop, Resolume, etc.): video or an image drawn over the mask will land exactly on the real fixtures;
- as a stencil: finished video is cropped by the mask, so light remains only where fixtures are actually installed;
- as a layout diagram for an artist or contractor who doesn't have Light Stream or the project;
- to check the layout itself — the mask clearly shows gaps, extra pixels, and uneven lines.
By default the mask size matches the size of the Mapping field, so one mask pixel corresponds to one project pixel, and you won't need to align content with fixtures manually.
How to open the window
- In the main menu, select View – Export Mask.
- The Export Fixture Mask window opens. On the left are the save buttons and parameters, on the right is a preview of the future file.
- The preview updates immediately whenever any parameter changes, so you can see the result before saving.
The mask is drawn in pure white on a transparent background. In the preview, transparency is shown as a gray "checkerboard": anything that looks like the checkered background will be transparent in the saved file.
What goes into the mask
- All fixtures and splines of the project, regardless of selection and of which composition is open. The mask describes the fixture layout, not the animation, so effects, layouts, the background image, and the grid are not included.
- Fixtures with visibility disabled are not included in the mask. Nor are fixtures located in a port or converter with visibility disabled. This is a convenient way to export a mask for only part of the object: disable visibility for the unneeded fixtures, ports, or converters in the Fixtures window and export the mask.
- Fixtures placed outside the boundaries of the Mapping field are not included in the image — it is limited to the project size.
- The Fixtures and Splines checkboxes let you choose what exactly to draw: only individual fixtures, only splines, or both.
Window parameters
| Parameter | Description |
|---|---|
| Fixtures | Draw individual fixtures in the mask. Enabled by default |
| Splines | Draw splines in the mask. Enabled by default |
| Fixture Size | Size of the white dot for an individual fixture. Set in pixels of the Mapping field, default value 1. Fractional values are allowed |
| Spline Size | Thickness of the white line (dot size) for fixtures on splines, in pixels of the Mapping field. Default value 1 |
| Texture Width | Width of the saved image in pixels. Equal to the width of the Mapping field by default |
| Texture Height | Height of the saved image in pixels. Equal to the height of the Mapping field by default |
| X2 Size | Doubles the texture's width and height. The button works as long as the result does not exceed 8192 pixels per side |
| 1/2 Size | Halves the texture's width and height |
| Reset | Returns all parameters to their default values, and the texture size to the size of the current project |
Below the size-change buttons, the current ratio of the texture to the project size is shown as 1.00x / 1.00x — separately for width and height. A value of 2.00x / 2.00x means the mask is exported at twice the size of the project. Make sure both numbers match: if they differ, the image will come out stretched, and content drawn against such a mask will not align with the fixtures.
The specified parameters are remembered by the program and will be suggested the next time the window is opened.
Working with the preview
The preview can be examined in detail without changing the file itself:
- mouse wheel — zoom the image in or out;
- hold the mouse wheel — pan the image;
- right mouse button — reset the zoom and position to their initial state.
Zooming in on the preview is useful to make sure the fixture dots haven't merged together and the spline lines aren't broken.
Saving the mask as a single file
- Enable the needed Fixtures and Splines checkboxes.
- Set the dot and texture sizes, check the result in the preview.
- Click Save As….
- Specify the folder and file name, then click Save.
The mask is saved in *.png format with a transparent background. Everything shown in the preview goes into a single file.
Saving a separate file for each fixture
The Save Each button exports not a single overall mask, but a separate image for each fixture and each spline of the project. This is needed when content is prepared separately for each element of the object — for example, when each line has its own animation.
- Enable the Fixtures and Splines checkboxes — only the marked types are exported. If both checkboxes are cleared, the button is unavailable.
- Click Save Each.
- Choose the folder where the files will be placed, and click OK.
Each file receives the name of the fixture or spline from the Fixtures window and the extension .png. If a file with that name already exists in the folder, -d is appended to the new file's name, so previously saved masks are not overwritten. The texture and dot sizes are the same for all files and are taken from the window's fields, so the individual masks align exactly with each other and with the overall mask.
To make the files easy to distinguish, give the fixtures and splines clear names beforehand in the Fixtures window.
Choosing the mask size
- For most tasks, the default size is enough — it equals the project size, and no alignment is needed.
- If there are many fixtures and they merge into a solid blob on the mask, enlarge the texture with the X2 Size button. The dots will become larger along with the image, and the proportions will be preserved.
- If content is being prepared at a resolution higher than the Mapping field, export the mask at the content's resolution — but as a multiple of the project size, so the width-to-height ratio stays the same.
- The maximum side size is 8192 pixels. Very large masks take longer to compute and take up a lot of space.
- The Fixture Size and Spline Size values are set in project pixels and increase along with the texture. Increase them separately only when the dots need to be made noticeably larger than the actual pixel pitch — for example, to get a solid outline of the object.
- If you're unsure about the current values, click Reset and start over.