The frame duration in milliseconds.
The frame filename. When sprite sheet image is splitted by layers and/or tags (in which case multiple definitions exists per frame) then this filename property contains crucial information like the layer name, tag name and the actual frame number which is not the same as the frames index within the frames array. So without parsing this filename it is quite impossible to correctly import a splitted sprite sheet in a universal way because the filename format can be freely customized during export in Aseprite and an importer can't know this format.
So the easiest way is to not enable the "Split Layers" and "Split Tags" feature of Aseprite so the element indices within the frames array are the actual frame numbers which start by 0 and you can completely ignore the frame filename. But then you lose other features like control over the frame layers.
This is a very annoying flaw in Aseprite's JSON format. Consider up-voting https://community.aseprite.org/t/10158 to hopefully get a better solution in the future.
Rectangle of the frame within the sprite sheet image.
True if frame is rotated within the sprite sheet image to save space. As far as I know Aseprite doesn't
support this so this is always false.
The actual frame (sprite) size.
The trimmed rectangle within the sprite. Will be the same as sourceSize with coordinates x=0 y=0 when frame is not trimmed.
True if frame was trimmed by selecting "Trim Sprite" or "Trim Cels" in Aseprite.
Generated using TypeDoc
A frame definition within a frames array when selecting Array format during export in Aseprite. This is the same as the Frame type but with an additional filename property.