SGO Mistika Stereo 3D Calculator

The SGO Mistika Stereo 3D Calculator can be downloaded from the Android market.

How to use the SGO Mistika 3D Calculator

The calculator has 3 main screens:

-        The Settings View; contains the main the configuration settings.

-        The Calculus View; performs the stereo calculations.

-        The Screen View; view and manipulate parameters related to screen viewing.

To move from one View to another, press on the background and slide horizontally.

The Settings View

Settings View

The Settings View enables the user to configure the calculus settings we want to use. Those are:

Small Units: Preferred unit to measure small distances, such us Interocular distance, Focal length, Screen sizes and Disparities.

Large Units: Preferred unit to measure large distances, such us the distances on-set, and the spectator’s distance from the screen.

Camera Model: Defines the camera being used, and automatically sets the Sensor Width and Sensor Height. If the camera you are using is not in the list, you can manually adjust the size by selecting “User Defined”.

Sensor Width: The sensor width is automatically set based on your Camera Model. To set it manually, select the “User Defined” Camera.

Sensor Height: The sensor height is automatically set based on your Camera Model. To set it manually, select the “User Defined” Camera.

Screen Size: The target screen size defines where the stereo 3D footage will be displayed. There is a list of standard sizes, but you can select a different one selecting “User Defined”.

Screen Width: Screen width is automatically set based on the selected Screen Size. To set it manually, select the “User Defined” Screen Size.

Spectator Dist.: Distance from the spectator to the screen.

Interocular: Spectator interocular distance.

The Calculus View

Calculus View

This view allow us to perform the stereo 3D calculus.

How to use the calculus view

The calculus view has 3 main areas.

-        On the top it has the scale area. This allows the user to select how fast we want to change numerical values. x1 means it will use unit increments, x10 will use increments of 10, and so on.

-        On the left there is a column of circular option buttons. Only one will be selected (enhanced in green), and defines what parameter the user wants the calculator to automatically calculate. The selected parameter will be automatically recalculated every time any other value is altered. For example, if we want to calculate the Positive depth budget, select it, and then, every time any other value is changed the positive depth budget will be calculated for the new settings.

-        The central area includes all the parameters used for calculations.

The calculus view parameters

The parameters on this view are:

Focal Length: Camera Focal length we are using.

Max. Dist.: On set maximum distance. The distance to the furthest object on set. Just to the right of the name there is an infinite button. It is used to define the situation where the furthest object is really far away so it can be considered infinitely far. Such us with landscape environments.

Converg. Dist.: Convergence distance. The distance from the camera to the point they are aiming at – regardless of parallel or converged shooting.

Min Distance: Minimum distance. The distance from the camera to the closest object on set.

Max Interaxial: The distance between the cameras.

Roundness: Roundness represents the depth relationship between the real scene and the projected scene. Its measured in percentage. To better understand this concept, lets suppose we shoot a perfect sphere.

-        A Roundness of 100% means the perception of the sphere in the projection will be perfect. That is, it will be an sphere.

-        A Roundness below 100% means the sphere will be flattened on the projection and will be perceived as an oval flatten in Z. The lower the Roundness is, the more flattened it will be.

-        A Roundness over 100% means the sphere will be extruded in Z on the projection and will be perceived as bigger in the Z axis than in the X, and Y.

A color visual alarm tells you how far are you from the perfect roundness (100%). changing the number colour from green (good) to Red (bad)

Pos.: Positive disparity. This is represented in screen units and in percentage. If the positive disparity becomes bigger than the interocular distance, a visual alarm will advise you by changing the disparity numbers colour to red.

Neg.: Negative disparity. This is represented in screen units and in percentage.

How to change the calculator values

There are 3 ways to change the values.

Using the increment/decrement arrows

Every time you use the arrow, the value will be incremented or decremented the amount selected in the scale area.

Holding and sliding the value

If you press on the value box and slide your finger horizontally or vertically the value will be increased (moving up or right) or decreased (moving left or down).

Although the increment/decrement value will depend on how much you move, the increment/decrement speed will depend on the selected scale value.

Double clicking the value

If you want to enter a specific value, double click on the value box. A dialog will pop allowing you to enter a number.

The Screen View

Screen View

On this view is displayed the parameters related to final image display. Its components are:

The Screen representation: This is a visual representation of the screen. On it is shown the positive and negative disparities in percentage of the screen size as well as the distance in screen units.

If the Far disparity is uncomfortable for the spectator, the display will show an ‘uncomfortable’ warning. This warning can be either slightly uncomfortable or uncomfortable depending on how strong it is.

If the far disparity is too big to be perceived as 3D by the spectator, the warning will say Double Image!!!.

Screen Size: This is the same value as in Settings View. It is available here as it is strongly related with this view.

Screen Width: This is the same value as in Settings View. It is available here as it is strongly related with this view.

Spectator Dist: This is the same value as in Settings View. It is available here as it is strongly related with this view.

Roundness: This is the same value as in Calculus View. It is available here as it is strongly related with this view.

Pos: This is the same value as in Calculus View. It is available here as it is strongly related with this view.

Neg: This is the same value as in Calculus View. It is available here as it is strongly related with this view.