3D Coordinate System

The Immersitech libraries can place each participant into a 3D position, but knowing which axis x, y, and z refer to is important. Moving along the x axis will move a participant left or right, moving along the y axis will move a participant up or down, and moving along the z axis will move participant forward or backward, all three relative to the center point (0,0,0). Also note that the unit describing these x, y, z coordinates is Centimeters. Therefore, a participant at (15,-10,50) is 15 centimeters to the right of the center, ten centimeters down from the center, and 50 centimeters in front of the center.

Another important feature of the Immersitech 3D system is what we refer to as "heading". To know the direction of a source to a listener, we must also know which direction the listener is facing. Given the heading, we have all the information needed to perform an accurate 3D rendering, and so this information will always accompany the position.

The Immersitech library also has several more advanced controls if you would like to fine tune the 3D rendering experience. Note that the following parameter only apply if the IMM_CONTROL_MIXING_3D_ENABLE control is active.

The first is the IMM_CONTROL_MIXING_3D_ATTENUATION parameter. As a source moves further from a listener, its volume will decrease. This parameter allows you to control precisely the drop in decibels that a source will undergo for each additional meter they move away from the source.

The second parameter is the IMM_CONTROL_MIXING_3D_MAX_DISTANCE parameter. This parameter allows you to specify at what distance you would no longer like distance attenuation to occur. This way you can prevent participants from no longer being audible if they move very far away from the listener.

The third parameter is the IMM_CONTROL_MIXING_3D_REVERB_ENABLE parameter. By default, reverb is applied to more accurately localize the source in the room. However, if you don't want the reverb or prefer the sound without, this control will allow you to disable it. Note that the source will still attenuate even without the reverb enabled.