Parameters, animation, stages, and GIF/MP4 export

Animation lives in Eidolang rather than a separate canvas state. 2D, 3D, staged playback, and GIF/MP4 export share one timeline, keeping screen playback aligned with exported frames.

Parameter sliders

param r 1 range 0.5 4 step 0.1
circle c O radius r

Every param appears in Params. The figure reevaluates while dragging; release writes the value back to the command. Declare range for a useful complete slider interval.

Continuous animation

animate r duration 2s mode pingpong

The target must be a parameter or a bound object with writable freedom. Options include:

• mode loop, pingpong, or once;
• speed or duration;
• over t0 t1 for a restricted interval.

Status-bar Play/Pause controls preview. Stop commits current animated values to literals as an undoable edit.

Staged presentations

stage givens duration 1.2s reveal fade
point A -3 0
point B 3 0
segment base A B

stage result duration 1.2s reveal draw
point M = midpoint(A, B)
hide base transition erase duration 0.6s

• Objects before the first stage are persistent background.
• reveal cut|fade|draw controls new objects.
• clear hides earlier stage objects without deleting dependency values.
• show/hide support cut, fade, draw/erase, and their own duration.

Staged scripts gain previous, play/pause, reset, next, and a full scrubber. Editing opens at the completed final state; Play from there restarts from stage one.

Export GIF and MP4

Open Export and select GIF or MP4:

1. Choose Current view or Fit content; 2D also supports a custom rectangle.
2. Decide whether to include the coordinate grid.
3. Choose raster scale, frame rate, and either a preset or custom positive duration. Defaults come from Settings › Export defaults.
4. A staged script exports its stage timeline; ordinary animate exports one complete motion.
5. 3D additionally offers camera orbit.

Both formats render the same frames from the same timeline, so the choice is only about encoding. Duration initially comes from the script timeline, but the export dialog can override it with a preset or custom value. Eidograph caps the total frame count to protect memory and marks a capped export. Lower frame rate, duration, or raster scale to reduce size.

Choosing between GIF and MP4

	GIF	MP4
Encoding	palette, up to 256 colors per frame	H.264, full color
File size	grows quickly with length and detail	much smaller at the same length and scale
Playback	loops by itself anywhere images display	needs a video player; stays smooth for long or high-resolution clips
Good for	chat, forums, and issue trackers	slides, video editing, and lecture recordings

Notes that apply to MP4:

• The video is silent and never transparent; the export dialog hides the transparent-background switch for both animated formats.
• H.264 needs even pixel dimensions, so an odd export width or height is rounded up by one pixel.
• Encoding uses the system's H.264 encoder. If the system cannot encode H.264 at the chosen size, the export reports an error and GIF remains available.

Keep animation robust

• Animate a parameter rather than a derived result.
• Keep the construction valid across the full range; arc endpoints, for example, must not coincide.
• Use moderate samples for numeric intersections and surfaces.
• Play from start and check Diagnostics before export.
• To keep a final pose, Stop to write current values, then save the project.