Light Lab Beta Program – Build 4 Release Notes

Light Lab Build 4 provides new features, like Props, as well as internal improvements to help us further develop the software. This article contains information specific to this build, and is subject to change before release.

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Props
You can now add and configure props in your light lab. We currently support a collection of primitive geometry, like spheres, cubes, and tori. We have begun work on allows you to provide custom geometry, as well as adjust the materials that props are made of, but that work is not nearly stable enough to be included in a build, even as part of this beta program. For now, all props will have a white plastic finish.

File Compatibility
Files saved in the previous builds of Light Lab will open, but will not contain any props or fixtures, effectively making those files useless. We are still actively working on the file format to best suit future expansion, and this may not be the last time an update makes files incompatible. Thank-you for your understanding.

File Template
If you create a new file, you will find that now by default you are provided with six fixtures, three in the primaries of red, green, and blue, and three in the secondaries of cyan, magenta, and yellow, allowing for easy observation of additive mixing of light. In the future, there will be numerous template files to choose from for various situations, but for now the single file will have to do. Try adjusting levels and moving lights around to experiment with different real world scenarios. If you are looking for inspiration on some different angles of light you might try, try starting with the 12 standard distributions of light.

Performance
Be aware that many facets of this program remain rough and unoptimized. You may find performance to be sub-par on older iPads. This build displays information about the current frame rate along the bottom of the screen. Additionally, those using the macOS build will find a performance penalty since the application is actually being downscaled to 77% before shown on screen.

Color Library
While we currently license colors from Rosco (Roscolux and GAM), Lee, and Apollo for use in Stagehand, we do not hold a license for their use in other applications at this time, and these negotiations will take longer than usual due to the COVID-19 public health crisis. We intend to provide these libraries of color in a future beta.

Camera Controls
The camera in Light Lab is currently controlled using the default iOS system gestures, which are at times intuitive and at other times unfit for their purpose. These will change in a future beta!

• Pan with one finger to rotate the camera around the scene.
• Pan with two fingers to translate the camera on its local xy-plane.
• Pan with three fingers vertically to move the the camera forward and backward.
• Double-tap to restore the camera to the default view.
• NOT RECOMMENDED Rotate with two fingers to roll the camera (rotate on the camera node’s z-axis).
• NOT RECOMMENDED Pinch to zoom in or zoom out (change the camera’s field of view).

What We Currently Model
As you may well be aware, the physics behind light is complicated on a good day. We are attempting to, to the best of our ability and the ability of modern GPUs, achieve a visually accurate model of light. The following are aspects of light that we currently take into account during rendering.

• Lamp color temperature is used to adjust the output color of the fixture, just like a lamp mixed with gel would.
• Individual beam and field angles.
• Colors mix on surfaces.
• Colors mix in atmospherics.
• Shadows take on other light that strikes that area, allowing you to fill shadows from key lights with color.

Known Issues

• Atmospheric effects can not be disabled or adjusted.
• Atmospheric effects are not affected by objects casting shadows, like the cyc, allowing haze behind the cyc to be lit.
• Atmospheric effects can vary in appearance greatly depending on the angle at which you view them. While this is true in real life as well, it is not true to the extent that it is inside Light Lab.
• Editing a fixture and tapping out of the editor without first tapping the Back button will result in the fixture still appearing selected in the lab. To correct this, reopen the Fixtures editor, tap the incorrectly selected fixture, and then tap the Back button.
• Gobos are not supported.
• Shutter cuts are not supported.
• The color picker can extend past the edge of the editor.
• All fixtures are currently in need of bench focusing, and exhibit a severe hotspot at the center, which is mostly evident in the atmospherics.
• Amber shift is not taken into account as fixtures are dimmed.
• The sphere, cyc, and other aspects of the lab are still sparse, and will be replaced in a future build, perhaps with something resembling a certain light lab in Winston-Salem, North Carolina.