To create realistic looking lightening can be a challenge. If you examine photographs of lightening you will see the main strike is white with a fuzzy purple glow around the strike. The side branches are also considerably thinner than the main strike. Light also appears to Flash several times.
In the first keyframe, select the pencil tool, set line width 8.0, curve modifier (smooth). Draw a single erratic line from the top to the bottom. Now select a line width of 1.0 and draw some branches. Not all branches have to be attached to the main strike. Then select 0.5 line width and add the smallest branches.
Create 3 more keyframes all containing the same lightening strike in frame one. Select the 2nd keyframe, select the lightening strike, choose Modify>Curves>Lines to Fill. Then choose Modify>Curves>Soften Edges Distance 10 pixels, No steps 4, Direction expand. This will make a thicker fuzzy looking lightening bolt.
Select Frame 3, choose Modify>Curves>Lines to Fill. Modify>Curves>Soften Edges. Then select a purple color, select the Ink tool and fill the lines with purple. Now select the entire lightening bolt and convert it to a symbol. Insert>Symbol. This will permit you to alter the alpha property.
Double click on the graphic or choose Modify Instance, select the color tab choose alpha, change the alpha property to about 50%.
Frame 4 should be the same as the first frame. Add a 5th keyframe and make sure it is empty. Delete the lightening bolt. Now add another keyframe at frame 15. Nothing happens between frame 5-15 – this provides blank dark sky after the lightening bolt. Edit Edit movie.
Open you personal library Window>library and drag the lightening graphic onto the stage. Add a second keyframe in the layer at frame position 10. Play the movie. The lightening bolt should flash. Now you need to add some effects.
Import the Thunder sound effect (wav.file) and create a new layer. Drag the Thunder sound file into the first keyframe of the second layer. and play your movie. You can add additional lightening strikes and sound bytes.
Two flashes of lightening on screen with Thunder sound effect. You can flip one of the flashes so it appears to be coming from another direction.
Download the thunder.wav file and completed Flash movie here.
