AEGP Details

Have A Cookie

In cases where After Effects must preserve state information around the functions your AEGP calls (as when an artisan is rendering a frame, or a keyframer is adding and removing a series of keyframes from the same stream), you’ll call begin() and end() functions.

Typically, the begin function will return an opaque identifier, or ‘cookie’, which you must then pass to the functions being used. The end function will properly dispose of the cookie. See AEGP_StartAddKeyframes() (under AEGP_KeyframeSuite3) for an example.

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Modifying Items In The Render Queue

If you call AEGP_AddCompToRenderQueue (from AEGP_RenderQueueSuite1), or if the user manually adds or removes a composition from the render queue, all references to render queue items are invalidated. Similarly, adding or removing output modules invalidates any such references for each render queue item.

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Names And Solids

Solids have names in the After Effects UI, but not in their PF_LayerDef PF_EffectWorld / PF_LayerDef. Consequently, their names cannot be retrieved by AEGP_GetItemName (in AEGP_ItemSuite9) or AEGP_GetLayerName (in AEGP_LayerSuite9).

However, you can use the ItemH associated with them to AEGP_GetItemName (from AEGP_ItemSuite9).

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Reporting Errors And Problems

Use AEGP_ItemSuite>AEGP_ReportInfo() to report information to users, and identify your plug-in. AEIO plug-ins use the msg_func pointer contained in the AEIO_BasicData they’re passed (with every function) instead.

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Transforms: What Happens First?

After Effects computes rotation based on auto-orientation (towards path, or point of interest), then computes Orientation, then computes X, Y, and Z rotation.

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Accessing Pixels From Effect Layer Parameters

Use AEGP_GetNewStreamValue (in AEGP_StreamSuite5) to get the layer’s layer_id, then the new AEGP_GetLayerFromLayerID (in AEGP_LayerSuite9) to get the AEGP_LayerH.