Make an Aircraft Flap Rotate Properly

So you've made an aircraft model and now you're trying to convert it to a Poser figure. You need the flaps (or "ailerons") to move properly, but they should move at angle other than the usual x, y, or z-axis. How do we do this in Poser? Basically, we adjust the Orientaton of the part's joint center.

Applications used:

• Poser (any version)


1. First, we need to decide which model we want to use and load it into Poser. For this tutorial, we'll use the 747 (JumboJet) model, but feel free to use your own model.

• First, start Poser.
• For the sake of this tutorial, we'll use a brand-new, empty scene.
• To add the 747 (JumboJet) to the scene, go to your Figures Library, then the VP sub-section.
• Click on the thumbnail picture for the "JumboJet" and then click the "" button (Apply Library Preset).
Wait a moment as Poser adds the 747 (JumboJet) to the scene.
• Alternatively, add your own aircraft (or other vehicle) to the scene.
Poser screen 1

2. Find the flap/ aileron (body part) to work with. For this example, we'll work with the left, rear flap.

• I find it useful to work in "Wireframe" mode: hit Ctrl-3 or select "Wireframe" from the options under Document Display Type.
• Switch to the top camera: hit Ctrl-T or select it from the camera menu.
• Adjust the camera so you are zoomed in on the part. Your screen should look similar to the image on the right.
Zoom in on the part you want to work with.

3. Adjust joint parameters, step 1 (using the top view).

• Open the Joint Editor by going to Window > Joint Editor.
• You should now see green and red lines on the screen, in the shape of a cross (+). If you don't see red lines, don't panic: red lines will not appear if a part has "children" parts connected to it.
The green line is the part's center point: the point at which the part will rotate around. In the Joint Editor window, the first set of boxes (the "Center Point") represent the green line's X, Y, and Z values.
The red line can be used to adjust or tweak the rotation of the part. In the Joint Editor window, the second set of boxes (the "End Point") represent the red line's X, Y, and Z values. For this tutorial, these values will be same as the green line's values.)
• Adjust the part's joint center by dragging the green line or by entering values in the Joint Editor:
To drag the lines, position your mouse over the center of the cross. Your cursor will turn into a circle and you will then be able to drag.
You can also manually enter values into the first box (x value) and third box (z axis).
Adjust the joint center (top view).

3a. Adjust joint parameters, step 2 (using the side view).

• Switch to the side camera: hit Ctrl-; (Left Camera) or Ctrl-' (Right Camera) or select it from the camera menu.
• Adjust the view so you are zoomed in on the part.
• Adjust the Y value (middle box) so the green and red lines are in the center of the part, again either by dragging or manually entering values into the boxes.
• Your screen should look similar to the image on the right.
Adjust the joint center (side view).

4. Which dial rotates the part?

• Using either the side view or top view, you can test the rotation of the flap: go to the Paramter Dials palette and test the xRotate, yRotate, and zRotate dials.
• Two dials will rotate the part incorrectly: set these to zero and ignore them.
• For the third dial, let's rename it: double-click on the xRotate dial and enter a new name, such as "UpDown".
Adjust the rotate dial.

You're probably asking, "Sure, the part rotates, but it's still off-center and rotates through the wing!" We need to make one more adjustment:

5. Joint orientation

• Switch back to the top view.
• If you look carefully, you'll see that the green + does not line up with the polygons in the "flap" part. This is what's causing the rotation to be off-center.
• The trick is to adjust the "Orientation" dial: these are the three dials just below the boxes for the joint center.
• Experiment with the three dials. Like the Rotate dials, one will obviously be correct: use this dial to line up the green + with the edge of the polygons.
In this example, the Orientation for yrot and zrot needed to be adjusted: yrot has been set to 25.5 and zrot has been set to 6.7.
• Your screen should look similar to the image on the right.
Adjust the orientation.

That's it! You're all done. Close the Joint Editor (click the X in the top, right-hand corner of the Joint Editor) and save the figure back to the Figures Library. (Don't forget to switch back to the Main Camera or switch to another Document Display Mode.)