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--- visual3d:documentation:modeling:segments:create_coda_pelvis_relative_to_anatomical_landmarks [2024/07/16 16:57] – removed sgranger
+++ visual3d:documentation:modeling:segments:create_coda_pelvis_relative_to_anatomical_landmarks [2024/07/17 15:45] (current) – created sgranger
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+====== Create CODA pelvis relative to anatomical landmarks ======
+Create CODA pelvis relative to anatomical landmarks.
+The segment coordinate system for the CODA pelvis is the mid-point between the ASIS markers. The anatomical landmarks are actually posterior to the ASIS markers because the motion capture system tracks the center of the marker.
+This is a modest error, but it can be corrected by creating landmarks that are posterior to the ASIS markers by the radius of the motion capture marker.
+=== Step 1. Confirm the subject metric containing the marker radius. ===
+If the metric doesn't exist, create a new metric.
+Switch to **Subject Data/Metrics** TAB.
+{{:SegmentExample4_1.png}}\\
+Select **Add New Item** and enter in the name **Marker_Radius** and the value.
+{{:SegmentExample4_2.png}}\\
+In this example, the marker has a diameter of 1.2 cm. Visual3D uses MKS units, so the value is 0.006 meters.
+**Note:** If the radius is not consistent with your marker radius, modify the value.
+=== Step 2. Create landmarks for the ASIS markers ===
+{{:SegmentExample4_4.png}}\\
+**Note:** the ML Edit box contains the expression **-MARKER_RADIUS**
+{{:SegmentExample4_5.png}}\\
+**Note:** the ML Edit box contains the expression **-MARKER_RADIUS**
+=== Step 3. Create a CODA Pelvis ===
+{{:SegmentExample4_6.png}}\\
+In this example, the locations defining the segment coordinate system for the pelvis are the landmarks **RT_ASIS** and **LT_ASIS**, and the marker **SACR** located at the midpoint of the PSIS markers.
+The tracking markers are **RASI**, **LASI**, and **SACR**.
+{{:SegmentExample4_7.png}}\\