Eternity supports the ANIMDEFS lump inherited from Hexen and extended by GZDoom. Not all GZDoom features are available yet, though, but enough to improve cross-port mod compatibility. As in GZDoom, ANIMDEFS defines both animations and switches. ANIMDEFS in Eternity is meant only for compatibility with other ports; if you want to target only Eternity, use EDF instead. All features available in ANIMDEFS are possible in EDF.
Example of feature not available in ANIMDEFS but available in EDF: animated warping textures, or animations which only warp at certain textures
flat <name> pic <name or offset> tics <duration> pic <name or offset> rand <min duration> <max duration> texture <name> pic <name or offset> tics <duration> pic <name or offset> rand <min duration> <max duration> flat <name> range <name> tics <duration> texture <name> range <name> tics <duration> warp flat <name> warp texture <name> warp2 flat <name> warp2 texture <name>
warp and warp2 are currently identical, but may change if extra compatibility with GZDoom is added. To be sure of the effect, use EDF instead. The SMMU-based swirl effect in Eternity is defined as warp2 in GZDoom.
switch <name> on pic <name> tics 0 [sound <name>] [off [pic <name> tics 0] [sound <name>]]
Currently multi-frame switches aren't supported, but the GZDoom-based syntax requires tics to be present whenever a pic is set, that's why it has tics 0.