The Mask menu lets users control the boundaries of a "Scene Space Mask".
A scene space mask is a virtual 3 dimensional rectangle that tells NextStage what should and shouldn’t be included in a depth matte.
A depth matte is a 2 dimensional image that defines what pixels are and aren’t transparent. This matte is exported as the alpha channel during HD Capture.
The pixels in the infrared view will be color coded one of three values.
Green pixels are within scene space mask, and objects shaded green will be included in the depth matte.
Red pixels are outside the scene space mask and will not be included in the depth matte.
Blue pixels are unknown. These are pixels that the Kinect has no depth information for, so it is unknown if they are inside the scene space mask or not. These will not be included in the depth matte.
The unknown pixels are shaded blue to help debug issues with the Kinect. While the Kinect does a very good job of calculating depth, there are pixels in every frame it cannot account for.
The boundaries of the depth mask will appear as a white line overlaid on the infrared image.
The position of the boundaries can be manually set using the 6 inputs in the menu. These values are in meters, and the zero point is the same as the marker set’s origin point.
Any value can be set for these boundaries, as long as it does not go past the opposite boundary. For example, you cannot flip the mask by moving the left side past the right side.
The boundaries of the depth mask are aligned with the marker set and the main axis of NextStage’s world space. In order to rotate or change the orientation of the depth mask, you will have to change the orientation of the marker set.
This button will reset the boundaries to the default 3 meter cube.
There are three sliders above the Kinect’s view you can use to change the boundaries of the mask. On the left side drag the top and bottom knobs to position the top and bottom of the mask. The left and right knobs at the bottom control the left and right sides of the mask. Finally the two knobs to the right set the front and back boundaries of the mask.
You can also grab the center of the slider do drag both knobs at once. Or hold down the alt button while dragging a knob to scale up or down.
While these sliders are limited to the size of the screen, you can increase the range of the sliders by entering a larger value into the input field. For example, if the Left Slider will only go up to 2 meters, by entering 4 into the left value the slider will now let you select up to 4 meters.
The Center Sliders button will “refocus” the sliders in the viewport. This does not change the values of the boundaries. It only changes the minimum and maximum values for the sliders, making them easier to work with.
Auto Load Mask
With this enabled NextStage will remember whatever settings you last used so you don’t need to reset the mask every time you load NextStage.