Flash Tips

Among the other export formats that Moho offers, you also have the option to output Flash SWF files. SWF is a format created by Macromedia as a way to deliver animated vector artwork and interactive applications. Flash animations are very common on the web, and most users already have the Flash player installed on their computers. Because Moho is also vector-based, there are enough similarities to make it possible for Moho to export SWF files.

However, Moho and Flash are not completely compatible. Therefore, not all the features of Moho can be exported successfully to Flash. In addition, because Flash is a web format, small file size is important - there are certain issues to keep in mind when working with Moho if Flash is your intended output format.

When exporting SWF files, you may want to use Macromedia's Flash authoring tool to combine multiple SWF files, add extra elements, sound, etc. Be aware that Moho's SWF files are compatible with Flash MX and later - Flash 5 and earlier are not able to load Moho-created SWF files.

What Can be Exported

Most common objects in Moho can be exported to Flash. These include:

• vector layers
• fills/outlines/colors
• transparency
• gradients
• variable-width lines (try to use these sparingly - see below)
• bone warping of vector layers
• image layers (PNG and JPEG only, and only if they are not warped by a bone layer)
• particle layers (careful - a complex particle effect can easily overwhelm Flash)
• a soundtrack can be exported if it's in MP3 format, and at either 44100kHz, 22050kHz, or 11025kHz sample rate

What Can't be Exported

On the other hand, some things in Moho are just not compatible with Flash, and cannot be exported to a SWF file. The following list covers the most important of these objects and effects.

• brushes
• fill and line effects (except gradients)
• layer effects (shadows, shading, layer blur, motion blur, etc.)
• image warping or 3D movements in image layers
• image layers that use progressive JPEG images (Flash can't handle progressive JPEG images)
• layer masking
• 3D layers

How to Create Efficient Flash Files

When you're creating an animation with the intent to produce an SWF file as output, there are several things to keep in mind. An important concern with SWF files is keeping the file size down. The key way to do this in Moho is to keep as many layers "optimized" as possible. An optimized layer when exported to SWF will take up much less space than a non-optimized one. (For other formats, like QuickTime or AVI, it doesn't matter.) You can tell which layers are optimized by looking for a little red dot next to the layer's icon in the Layers window:

Notice the red dot by the optimized layer.

A new layer is optimized to start with, but depending on the effects you apply, that optimization can go away. The following things will "de-optimize" a layer. Note: a non-optimized layer will still export to Flash, it just won't be nearly as efficient.

• 3D camera movements (this will de-optimize all layers in the project, so it should be avoided if possible when targeting SWF)
• 3D layer rotation (X or Y rotation, or perspective rotation)
• layer shear
• a group layer that has 3D rotation or shear will cause all of its sub-layers to be non-optimized
• uneven scaling in the X and Y directions
• point animation
• bone animation (see below)

Bone animation is a common cause of non-optimized layers. What's happening is that because Flash doesn't have a bone system like Moho, Moho needs to export a lot of extra information for Flash to be able to produce the same effect. One way to use bone animation and to stay optimized is to attach a vector layer to a single bone, instead of letting the bones warp all the points in the vector layer. The vector layer will then remain optimized. While you can't do this in all cases, sometimes you can break up a character into multiple body parts - some parts will be warped with the bones, and some will be attached to a single bone. At least some parts of the character can remain optimized.

Here are some other things to think about when exporting to SWF:

• Consider using a lower frame rate (12 fps, for example) for your animation. Fewer frames means a smaller file.
• If some of your layers can do without any animation at all, or just layer translation/scaling/rotation (background scenery, props, background characters, etc.), that can save a lot of space.
• If most of a layer is stationary, except for one small object, move that object into its own layer if possible. Example: a character who is waving his arms, but is otherwise still - move the arms into a separate layer from the rest of the body. The body will remain optimized and take up much less space.
• If an object sits still for a time with no animation, consider replacing it with a non-animated object for that time period.

What to Avoid

If your goal is to create a SWF animation, there are some things you should try to avoid. Besides the effects that just are not possible to export, you should try to avoid the following effects if possible. These are all things that can be exported - it's just that they make for a less efficient SWF file. Of course, you won't want to avoid all of these things all of the time. However, if you plan your animation carefully, and use as few of the following effects as possible, the resulting SWF file will be smaller, and will load quicker over the web.

• 3D camera moves - no Flash optimization is possible when you're moving the camera around in 3D. Simple side-to-side pans and zooms are OK, but when you start using camera pan/tilt, Flash efficiency goes down the drain.
• Try to use as few control points as possible in your vector artwork.
• The freehand tool and the insert text dialog can generate a lot of points, resulting in a big SWF file.
• Limit the use of variable-width lines. It's easy to overwhelm Flash with the complexity of variable-width lines, making the resulting SWF file play back unpredictably. Read this for more information. If possible, only use variable-width lines in SWF-optimized layers.
• Avoid compound shapes (two adjacent circles filled as one, shapes with holes, or figure 8's).