PowerPoint Tips & Tutorials

Animate a revolving earth

Here's a trompe l'oeil effect of the earth revolving. I learned this in Flash and have been trying to reproduce it in PowerPoint for a while. It doesn't look as nice in PowerPoint, because Flash's vector graphics are sharper, but it's still nice.

Look at the animation. (1.8 MB) Note that the AVI file isn't as smooth as the PowerPoint animation itself.

I think of this as a nice animation to show when the audience is entering the room, or during breaks. Maybe you can think of other uses.

Here's a static image of it.

Here are the steps:

1. Find an image of the night sky and insert it onto the slide, resizing as necessary to cover the entire slide.
2. Draw a large circle and center it on the slide. Remove the outline and use a fill color that doesn't exist anywhere in the photo. Red might be a good choice.
3. Duplicate the circle and move the duplicate to the side for now. You'll need it later.
4. Select the image and the circle, right-click, and choose Save as Picture. In the dialog box, choose the PNG file type, because PNG supports many colors and transparency. Save the image in the same folder as the presentation.
5. Delete the image and the circle, or move them off the slide if you think you might need them again.
6. Insert the PNG picture that you saved. Place it so that it completely covers the slide.
7. Select the picture. (If the Picture toolbar isn't displayed, right-click any toolbar and choose Picture from the list of toolbars.) Then choose the Set Transparent Color button and click the circle shape. It becomes transparent and you should see the white slide through the circle -- which is now a hole.
8. Move the duplicate circle that you saved and place it in the hole. It should fit perfectly; if you want, you can make it a little bigger than the hole.
9. Double-click the circle to open the Format AutoShape dialog box. From the Fill drop-down list, choose Fill Effects and use the Gradient tab to change the fill to a black and white gradient, using the From Center type, with the white at the center and the black around the circumference. This gradient will create the illustion of a globe.
10. Right-click the circle and choose Order > Send Backward.
11. Now comes the hard part. Find a map of the world with blue oceans and green land. I modified mine in Photoshop. Make sure that there is space for the Pacific Ocean at one end. Then duplicate the map and group the two side by side. (I've included this map in the download at the end of this tip.) The height of the map needs to be just a little more than the diameter of your circle, so resize it if necessary. You need the result to be one image file. Insert it onto the slide, resize it, and then use the same Save as Picture command you used earlier to save it as a PNG file in the same folder as the presentation.

12. Draw a rectangle the same size as the map. You can now delete the map image, since you saved it.
13. Double-click the rectangle and remove the outline of the rectangle. In the Fill section, choose Fill Effects from the drop-down list and use the Picture tab to insert the image of the map that you saved. When you click OK and return to the Format AutoShape dialog box, drag the Transparency slider to 50%.
14. Place the map to the right of the slide. Right-clic,, and choose Order > Send Backward. It should be behind the sky image, but in front of the black and white circle. Your entire setup should look like this. (Zoom to 25% to see it all.)

15. Select the rectangle/map and choose Slide Show > Custom Animation. In the Custom Animation task pane, choose Add Effect > Motion Paths > Left.
16. Select the motion path track drag, resize it so that it goes from the right side of the slide to the left side of the circle, as you see here.
    
    
17. Click the Play button in the Custom Animation task pane to see that you're getting basically the right effect.
18. Select the animation in the Custom Animation task pane and choose Timing from the drop-down list. From the Repeat drop-down list, choose Until Next Click and click OK.
19. Save your presentation and go into Slide Show view to see the result. Do you see a jerk at each repeat? I did; go back and make minor adjustments to the length of the motion path until you get the smoothest possible result. (This is the really hard part!)

Download the presentation and the image of the map.

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