Creating 3D Views

Defining a 3D View

To create a new 3D View, hover the cursor over “3D Views” in the left menu, then right click the mouse. You can now select “Add New”.

The 3D View Configuration Menu screen will open (see below):

The “3D View Configuration” window is composed of 5 panels:

  • New 3D Panel
  • Joining Diagrams
  • Solid Objects
  • Projection
  • Environment

The “New 3D Panel” controls the display of all markers (raw data and or computed data) and their colours. To add the display of one marker or all markers, click on the “Add” button  located on the top right of the “New 3D Panel” panel. A new line will appear inside the table. Choose the “Group” (usually “Marker” or “RefPoint”), the channel (the name of the marker or you may choose ‘[ALL]’ markers) and the colour to display. For example, the dialogue box above causes all markers to be displayed in green.

Note: the drop box only displays the available data type. If no filter option has been selected, then “HFilter” and “RefPointFilter” will not appear in the list.

To delete an existing display of marker(s), simply select the display to delete and click on the “remove” button 

The “Joining Diagrams” panel defines which joining diagrams are displayed. Each named joining diagram defines how markers are visually connected to other markers. To add a new joining diagram, click on the “Add” button  located on the top right of the “Joining Diagrams” panel. This opens the ‘Stick Figure Joining Diagram’ dialogue box.

An existing set of joining diagrams can be edited by clicking on the “edit” button 

located under the “Add” button. This opens the ‘Stick Figure Joining Diagram’ dialogue box.

The “Solid Objects” panel allows assignment of a geometrical model to a segment / object. The model is usually a representation of the bone(s) used for the 3D animation. Click on the ‘+’ to add a new object or the ‘edit’ button to edit a selected object. Both these actions open the ‘Solid 3D Object’ dialogue.

In the example below, the model file is a 3D representation of the right femur bone. There is a predefined list of bones but other models (and not necessarily a bone) can also be imported. The model files are wire frame objects formatted in an “.obj” file format. The 3D display of an object is purely for visualization. You can rotate, scale or move the bones relative to the segment coordinate system and it will not affect the analysis. The inertial properties of the segment are not applied through this function.

This dialogue box assigns a 3D representation to a segment / object (represented by markers). The dialogue box is composed of 5 panels.

First, choose the representing model of the object / segment through the “Name” combo-box. The display of the model as well as the attached coordinate frame will appear in the “Preview” panel just after selecting the object. Choose the marker which defines the origin through the “origin” panel. The origin of the bone is the part of the bone where the coordinate frame is attached to. Here for the femur it corresponds to the femur head/hip joint centre of rotation. The orientation of the display is controlled through two axes (X and Z). The longitudinal axis of the bone is defined by the proximal and the distal points (markers) of the segment (blue array). These two points (real and/or computed markers) are configurable through the “Z-axis” panel. Along those lines, the mediolateral axis is defined through the “X-axis” panel (red array).

An auto-scale can be applied by ticking the “enable” option of the “Auto-Scale” panel. If you enable this then the length of the bone will be defined by the two extreme points on the Z-axis.

The “Projection” panel (on the 3D View Configuration) allows the user to change the method for visually representing three-dimensional objects and scenes. There are 2 possibilities: “perspective” and “orthogonal”. The perspective view is an approximate representation, on a flat surface (here, the screen), of an image as it is seen by the eye. The orthogonal view represents the orthographic projection of 3D objects and scene onto a plane. Orthographic projection lends itself to making pictures look flat. In orthographic projection, all objects of the same size look like they are the same size, even if one is close to the camera view and the other is far from the camera view.

Five options are accessible from the “Environment” panel. The tick box marked “Show CODA Units” controls whether the 3D shapes of the CODA units are displayed. Each CODA unit is displayed at its real position compared to the lab coordinate system. The tick box “Show Force Plate” allows display of the outline of the force plate. The tick box “Show Grid Lines” allows display of the grid representing the floor. The tick box “Show Axis” allows display of the X and Y axes on the floor. At the end of each axis, an arrow indicates the direction of the axis. The tick box “Large Grid” displays a large grid representing the floor. Note: the tick box “Show Grid Lines” needs to be selected for this option to work.

Once a new ‘3D View’ has been saved, it appears in the menu tree on the left hand side, and may be selected for launch into a layout, editing, or removal, simply by right clicking its name and selecting the action from the drop down menu that appears:

Any number of ‘3D Views’ can be stored in the same Analysis Protocol.

Note that 3D view can only display Marker and RefPoint during real-time application. MFilter and RefPointFilter can only be displayed during playback (post-treatment).

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