OLT-Interactive Laser System Description

OLT utilizes the latest deep camera technology, with the standard version camera recommended for detection at a distance of 5 meters. Due to the suspension setup, the laser is typically suspended within 6 meters, taking into account the average human height. In addition to the previous tracking effects such as rectangles, rotated rectangles, Circle , Convex Hull, approximate polygon, and text, the latest version has added line effects, such as the automatic laser gate effect for head graphics.

 System Introduction：

The hardware composition of this interactive system is quite simple. A depth camera is used to detect the position information of people. The OLT software processes the camera’s images and performs real-time calculations for laser effects. The laser signal is output to the laser fixture through the laserdock box, and the OLT software also supports direct output of the laser signal to the BEYOND software.

When actually installing, it is best to choose a mini PC so that all the hardware can be put together, which also avoids the trouble of long-distance wiring. Of course, when debugging, you still need to connect a display, which requires a long-distance HDMI cable. Mouse and keyboard can all use wireless devices. The suggestion for the computer configuration should not be too inferior.

When actually installing, ensure that the front panel of the camera is aligned with the body of the laser fixture, and the center of the camera is aligned vertically with the outlet  of the laser fixture. The camera should be as close as possible to the outlet  and be firmly fixed.

 

Features：

 

The software is roughly divided into three parts: the left side is for camera-related settings, debugging parameters, and preview images. The middle section is for tracking effect settings, and the right side is for laser setting parameters and previews.

1. In the camera settings, when a camera is correctly connected, you can activate the camera image by clicking on the camera active button. If the camera is not correctly connected, this button cannot be activated normally. When the Auto Exposure button is turned on, the exposure and gain sliders below it cannot be adjusted. In situations where the laser fixture is suspended at a high height and the desired detection distance is greater than what the auto exposure can achieve, manual adjustment of exposure and gain can be used to meet this need.

In the general settings, the “Capture” button can be used to take a base image when there is no subject in the frame, which is useful for tracking calculations in complex environments, focusing only on moving objects. For example, if there are clearly detectable stationary objects in the camera image during a blank capture, this image can be captured and compared with the image when there are people present to perform comparative calculations. If you have previously captured a blank image, you can click the “Reset Image” button to reset this base image to a blank state.

The “ImgSize-Image Size” option can be used to zoom in and out  the camera’s image. Since the actual field of view (FOV) of the camera in use is 66 degrees, which is slightly larger than the 60-degree angle of the laser fixture, the camera image can be appropriately enlarged to better match the two images.

The “MapFac-Mapping Factor” option is used when the laser fixture is suspended too close to the ground, typically requiring a distance of more than 3 meters. If it’s less than 3 meters, it can cause significant deviation between the laser fixture image and the tracking position when people are near the edge of the image. In such cases, adjusting the mapping Factor can help with alignment. The default value is 1, ensuring that the camera and laser images are perfectly aligned.

The “X-offset” and “Y-offset” options are for correcting any misalignment between the camera and laser images due to installation errors. If the camera is accurately aligned with the laser fixture outlet vertically, the X-axis offset can remain at the default value of 0. When adjusting the Y-axis offset, ensure that the image size has been adjusted so that the widths of the laser and camera images are consistent, and then use the Y-axis offset to align the two images vertically.

If the camera is positioned farther from the laser light outlet, you might need to adjust the tilt correction(TiltCorr) option to better match the two images.

The “LowCut” option is for excluding the area below the ground, focusing on detecting moving objects above ground level. The “Filter” is for filtering within a certain time frames to enhance image stability. Increasing this value will increase image latency, and setting it to 1 will cause the image to fill in the effect. For effects that are based on real-time detection of object size (such as approximate polygon, ConvexHull, etc.), a setting of around 0.7 is usually recommended for improved stability.

The “DnSize-DenoiseSize” option is for edge noise reduction in the depth image; avoid setting this value too high.

The “Blur” option is another noise reduction method, adjust as needed, but don’t set this value too high either.

Below these settings is the camera’s depth image preview, allowing you to view the depth image and processing effects in real time.

 2.  The middle section of the software interface is for settings related to tracking calculations on the camera image.
In the Graph Style(GStyle) drop-down menu, you can switch between different tracking effects. 

The Rectangle style calculates the position and size of the tracking object based on the real-time camera image, and you can also view the calculation results in the camera’s real-time preview. This rectangle does not rotate.
The RotRectangle style can output a rectangle with a rotation angle.
The Circle style generates a circular pattern at the position of the tracking object, and the size of this pattern can be set to a basic size, which will also change with the size of the tracking object.
 
The ConvexHull style calculates the maximum outline shape of the block in the camera image, and you can use the PolygonSample(PolygonSam) slider to adjust the sampling size of this outline shape.
 

The Approximate Polygon style resamples the blocks in the real-time image to generate polygons with the set PolygonSample value.

The Text style can generate shapes based on the input emoji or letters, and you can choose between inner or outer shapes through the graphMode in the text settings.
 
The Linear style is the effect of the laser automatic door, and you can adjust the detection range of the picture through the DetRange option. The Minimum Detection Size(MinDeteSize) option is also specifically for this line style.
 
The Border Width (BdWidth) option can set the border width of the calculated result shape in the preview image, and setting it to -1 will fill the block.
 
The Minimum Tracking Area(MinTrackSize) option is applicable to other graphic styles except for the line effect. The Maximum Tracking Number (MaxTrackCnt) option can be used to set the number of tracks for other graphic styles except for the line effect. The PloygonSam option is only used for ConvexHull and Approximate Polygon styles.
 
The Tracking Image Composition(ImageComp) button can switch the composition effect of the original camera image and the tracking effect. When turned on, you can adjust the (OrginImg option) input brightness to adjust the input brightness of the original image.
 
The Circle Dot Size (CDotSize)option can generate smaller circles at the positions of each point in the generated shape, which can enhance the beam sense of the laser shape in the air. You can adjust the size of this small circle through this option. When the number of dots(CirDots) is set to 0, that is, no small circles are generated at the positions of the points in the shape. In fact, this option is similar to the Vertex Repeat option in the following BEYOND-related settings and the Vertex Hold option in the DAC settings. These options can all enhance the beam brightness of the shape and can be adjusted in conjunction with each other.
 
The Circle/Text Tracking Settings section is only applicable to these two graph styles. When you select the Text graph style, you can input emoji shapes such as heart shape in the text box.
 
The CircleSize option allows you to manually adjust the size of the shapes generated by the Circle style.
 
The Number of Sides (CirCleSides) option lets you set the number of edges for the Circle style to create different polygons.
 
To give the generated polygons different rotation angles, you can set this incremental rotation angle (IncreRot) value.
 
The Rotation Speed option adjusts the speed at which the shapes rotate.
 
The TextSize option is for adjusting the size of the text. Through the GraphMode option, you can select the OrginGraph, InsideGraph or OutsideGraph shapes of the text graphic, which can reduce the complexity of the graphic.
The Beyond Settings section is for configuring the connection with the Beyond software. This sample rate applies not only to the Beyond software but also to other DAC boxes. The Vertex Repeat option is usually set to 0. The VectorFrame button typically needs to be enabled so that the calculation related to the step and blanksize value can be handled by the Beyond software. The ResendImage button can be used to attempt to send the signal again if Beyond does not receive it properly.

Continuing on, we have the settings related to the laser output color. You can set different color modes. In the Constant color mode, you can set the color through the color palette on the right side of the software interface. When switching to the horizontal rainbow mode, you can adjust the rotation option to generate a rainbow effect that scroll in different directions. For the horizontal/circle/radial rainbow styles, you can adjust the period option to produce a smooth transition of colors.
 
3. The right side of the software is for settings related to the DAC box. You can use the Laserdock box or other laser interface boxes. The DAC-related settings directly affect the laser preview image in the lower right corner and are also applied to the output effects of these DAC boxes. The stepSize value and vertex hold options can be adjusted according to the specific output performance. The DAC Settings button opens adjustment options for other DAC boxes. The LaserOS Settings button opens settings related to Laserdock. The Open 2th wIndow button opens the tracking style switch interface on the extended screen.
 

Summary:

This system is designed for interaction with a single laser device. If you need to arrange multiple lasers in a channel for interaction, customization can be made as required.

 

1 thoughts on “OLT-Interactive Laser System Description”

  1. justin says:

    Version 2.0
    Added a preset access system that automatically loads the first preset upon startup. You can click to select and load the corresponding preset parameters, and after making modifications, click ‘Save’ to overwrite the corresponding preset. These presets correspond to the respective DATA1-6.olt files in the presets folder. Additionally, two anti-tracking effects have been added, which are the wave and poly anti-tracking effects. The wave anti-tracking effect includes three types of waveforms: sine wave, triangle wave, and noise wave. The placement of the laser is not limited to suspension; it can also be placed flat. Furthermore, the entire UI has been adjusted to be suitable for remote control via an iPad.

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