GUI guide

Create and save a project

1. Open Packrat and choose File > New Project or Open Project.
2. Add input folders from the toolbar, or drag folders onto the app.
3. Choose the packing settings, export format, and output path. Press EXPORT.
4. Save the settings as a .packrat project with Ctrl+S.

Each project opens in a tab. An asterisk (*) marks unsaved changes. Packrat stores paths relative to the project file where possible. You can also build a saved project from the command line.

Select and inspect frames

• Click a frame to select it. Hold Ctrl to add to the selection, or Shift to select a range.
• Right-click a frame, animation, or folder to preview it, ignore it, or change its glow and normal settings.
• Ignored sources remain in the list and are excluded from packing. Hover over a red entry to read its error message.
• Use the Sprites, Glow, and Normal tabs to inspect enabled outputs. If an output has several pages, use its page tabs to switch between them.
• Scroll the mouse wheel to zoom. Hold Space and drag to pan. Fit shows the whole sheet. The bounds controls show packed and source rectangles.

See Sources for supported files and animation names.

Packing settings

Control	What it changes
Max size	Maximum page width or height: 256, 512, 1024, 2048, or 4096 pixels
Algorithm	Packing method: MaxRects (default), Skyline, Shelf, or Grid
Trim mode	Whether to keep or remove transparent borders; see Trimming
Padding	Space between packed frames
Margin	Transparent pixels to keep around the trim bounds
Border	Space between frames and the edge of the page
More > Extrude	Number of edge pixels to repeat around a frame to reduce filtering seams
More > Alpha threshold	Minimum alpha value included in the trim bounds
More > Power of 2	Round page dimensions up to powers of two
More > Multipacking	Require one page, or add pages automatically when needed
More > Prepend root folder name	Include the input folder's name in exported frame paths

Packrat repacks in the background when these settings change. Use the CLI's --scale option to export at other sizes. Rotated packing and manual page assignment are currently disabled.

Generate effects

Under GENERATE, choose which outputs to write: Sprites, Glow, and Normal.

Glow uses a brightness threshold to select emitting pixels. Blur controls how far the halo spreads; padding reserves room for it.

Normal combines the image's alpha outline (Bevel) and brightness (Emboss). Its controls adjust roundness, raised or recessed shapes, softness, and the X and Y directions.

To change settings for part of the project, right-click a folder, animation, or frame and choose Set Glow/Normal Overrides. A frame override takes priority over an animation override, then the nearest folder override, then the global settings. An asterisk marks entries with overrides.

You can also provide manual glow and normal images. The browser labels show whether an effect comes from a file or from generation.

Export files

Choose Data Format, Image Format (PNG, BMP, or TGA), encoding quality, and an output base path. Press EXPORT. Keep each exported data file with the images it references.

Auto Export is off when a project opens. Enable it to write files after each successful repack. See Output files for filenames and the format pages for loading examples.

Shortcut	Action
Ctrl+N	Create a project
Ctrl+O	Open a project
Ctrl+S	Save the project
Ctrl+Shift+S	Save under another filename
F6	Open timing profiles

Preview Studio

Press Preview Assets above the atlas to browse the project. You can also double-click an animation or frame, or choose Preview from a frame, animation, or folder's context menu. A folder preview includes its nested folders. Use the browser filter to find an asset by path; hover over an entry to see its full path.

The preview offers five views:

View	What it shows
Color + Glow	Source color with glow added, including the halo outside the source canvas
Source Color	The source image
Glow Only	The glow map
Normal Map	The normal map
Lit Material	The image shaded using its normal and glow maps

You can overlay the source bounds and canvas center to check alignment.

Lighting

In Lit Material, drag on the canvas to move the selected light. Click a light handle to select and drag it, or use Move light. The settings panel controls height, color, intensity, ambient light, normal strength, specular highlights, and an optional blue fill light. In a small window, open these settings from the popup.

Packrat generates missing maps in the background using the asset's effect settings. You can preview them before exporting. Manual companion images take priority over generated maps, including after Reload. Open a companion image to inspect its pixels, or open the base image to see the combined result.

Animation playback

Use the timeline to scrub, step through frames, restart, or play. Choose Loop, Once, or Ping-pong playback. Source timing uses Aseprite frame durations; image sequences use the FPS control. Speed multiplies the playback rate in either mode. Scrubbing or stepping pauses playback.

All frames use the same preview canvas, so changes in trim bounds or glow size do not shift the framing.

Control	Action
Mouse wheel over canvas	Zoom around the cursor
Middle or right drag	Pan
Fit / F	Fit the complete animation canvas
1:1	Show source pixels at actual size
Space	Play or pause
Left / right arrow	Step backward or forward
Escape	Close the preview

Choose a checkerboard, dark, light, or custom background. Smooth sampling uses linear filtering; turn it off to inspect individual pixels with nearest-neighbor sampling.

Reload reads the source files again and regenerates maps. Automatic source refreshes keep the selected asset and view when that asset still exists. Preview controls apply to the current view and do not mark the project as edited.

The preview shows preparation progress while frames load. If a frame is too large or cannot be read, you can retry it, skip it, or choose another asset.