Followspot application

GrandMA3 can be used to perform automated followspot with any moving-head fixture of the market.

Patch Stage MArkers

Stage MArkers are standard fixtures in GrandMA that are able to be linked to the position of Targets received via PSN so that any moving-head fixture can point at them.

• Patch as many MArkers as you have targets in your Kratos Show.

The MArkers must be patched with a DMX address to work

Go to the Tracker View of the desired PSN server (see the tutorial Send Targets position to GrandMA3) and fill in the MArker ID column of each target with the Stage MArker you want to associate with it.

You should now be able to see the MArkers moving in the 3D view of GrandMA3.

You can find more information about GrandMA3 MArkers in their documentation

Patch tracking fixtures and check the Fixture Type

GrandMA3 allows you to use any moving-head fixture to perform followspot. But modifications and verifications need to be made in the fixture type to make sure they can operate well.

• Enable XYZ on the fixture types you want to use as followspot.

• Check that the values Physical From and Physical To of the Pan and Tilt attributes are corresponding to the real values given by the fixture manufacturer. You need to change theses values if it is not the case. To check those values, you need to edit the fixture type, and then edit the Pan and Tilt rows.

The manufacturers usually provide the full range of the Pan and Tilt attributes in the user manual of the fixture. Note that you will need to divide the values by 2 to get the Physical From and Physical To values. Make sure to put a - (minus) sign in front of the Physical From value

Calibrate fixtures position

Knowing the precise real life position of the fixtures you want to use to track people is crucial to perform good tracking. Using positions given by CAD files of the stage (like wysiwyg files) will not lead to good tracking as in real life the fixtures will always be installed in an not perfect way and have shifts in position and rotation. That is why it is important to perform a calibration of the position of each fixture you want to use for tracking. To do so, you have to use the fixture auto-calibration feature of GrandMA. To access this feature :

• Create a 3D Viewer view, and enable Setup Mode.

• Select the fixtures you want to calibrate, and click on "Calibrate Position" in the encoder bar.

You are now in the calibration window of the GrandMA3.

To calibrate a fixture, you havbe to make it point physically at 4 different points in the 3D view. You can input the physical coordinates of each point in the X, Y and Z fields of each P1, P2, P3 and P4 point.

Then, for each P1, P2, P3 and P4 point, you have to make the fixture point at the corresponding point on your stage. To do so, select your fixture, adjust the pan/tilt values accordingly, and click on Store P1, Store P2, Store P3 or Store P4 to store the Pan/Tilt values of the fixture for the corresponding point.

You can recall the Pan/Tilt values of a point by clicking on the Call P1, Call P2, Call P3 or Call P4 buttons

You can find more information about GrandMA3 fixture calibration in their documentation

Once you have stored the Pan/Tilt values for the 4 points, you can click on Solve to calculate the position of the fixtures.

Tips for calibration

On a standard stage setup, we recommend using the same rectangle used in the calibration process of the Kapta to calibrate the fixtures. This allows you, if you open the calibration window of Kratos, to have a clear top view of the stage and calibrate the fixtures without having to look at the stage directly : just point the beam at the 4 crosses making the corners of the calibration rectangle. You can also hover your mouse over the points in the calibration window of Kratos to see the coordinates of the points, and input them in the calibration window of GrandMA3.

Check the calibration

Once the calibration is done, you can check if the calibration is correct by pointing the fixtures at the origin of the stage. This can be done by selecting your fixture, going to the Position tab of the encoder bar, and clicking on "PanTilt 1 of 4" so that it becomes "XYZ 2 of 4"

Then, you can input the coordinates of the origin of the stage in the X, Y and Z. Set them to 0 to point at the origin of the stage.

Point a fixture at a target

Once your calibration is done and ready to use, you can point a fixture at a target by selecting the fixture, going to the Position tab of the encoder bar, and clicking on PanTilt 1 of 3 so that it becomes XYZ 2 of 3.

When pointing at a target, the X, Y and Z values that you input in the encoder bar will be the offsets from the target's position that the fixture will point at. You may want to set them to 0 to point directly at the target.

Then, to select the target you want to point at, click once again on the XYZ 2 of 3 button so that it becomes XYZ 3 of 3. You can now input the ID of the MArker you want to point at in the MArker field.

Your fixtures should now point at the target you selected.

You can store these encoder values to Position presets for easy encoding or busking, and recall them when needed. You can also store them in Cues to automate Tracking within Sequences, Timecodes, etc.