Further options with the Az-El panel are available by clicking on the "adv" button (just below the three color reset/normalize/center button) near the upper left corner of the panel. This pops up the window shown below:
The advanced transformation options are provided to allow rotations about a user defined center, as opposed to the default center of the objects, which is chosen by EVS OR MVS. The default center of an object shown in our viewer is midway between the min-max of the x, y and z dimensions. First, observe the default rotation center by clicking one of the spin buttons in the Az-El panel. Now let's rotate the object about a point that is located to the west of the object's center to demonstrate the use of the advanced transformation option.
a. Change the Az-El settings to a scale of 0.9, an elevation of 45 degrees and an azimuth of 180 degrees. Now, observe the default rotation center by clicking one of the spin buttons in the Az-El panel.
b. Now let's adjust the center of rotation by using the Alt Left-mouse action. First, depress the Alt button on the keyboard, then (while continuing to hold the Alt button) point to the anywhere on the right side of the mesh and press the left-mouse button. This action "selects" the object, AND activates the SEEK button in the upper right corner of the Az_El panel. Now press the SEEK button and your view will 'zoom-in' on this spot, thus establishing a NEW center of rotation. You may not have noticed this, but the center and translate values in the Advanced Transformations dialogue box were automatically updated. Although you could have manually entered values, the above approach is the most intuitive and efficient means of changing the center of rotation in the Viewer.
Observe your new center of rotation by clicking on one of the spin buttons in the Az-El panel and notice that the object is now rotating about a new center point. Also note that part of the object rotates outside the viewer window. The Translate options are provided to address this issue. The XY Translate dialogue boxes move (translate) the camera view when using the Az-El panel. Test this now by typing in a value of -108.0 into the Y Translate type-in box.
d. Wherever you select with an Alt-Left Mouse Click will appear in the bottom of this window. It will provide you with both coordinates AND the data value on the point on the surface.
e. Again Click on one of the spin buttons in the Az-El panel and notice that the object is still rotating about the new center point, but the object has been shifted over by the Translate function so the object is more visible in the viewer window during rotation. For further experimentation with these options click on the three colored button (reset/normalize/center) and repeat the above steps as desired.
For details and specifications on the advanced transformation options please read:
Module Libraries Help on Viewer