Fumy User Manual

Main Window
Fumy 2.0 is pretty close to a regular bitmap editor, it consists document window (s) and few tool panels. The app supports lots of input image formats (almost every image format supported by the MacOS) and can export merged bitmaps. Fumy has quite simple, minimalistic user interface and it’s really easy to lear the app. The topic below describe some app basics, plus we have a screencast showing the app in action.


Smoke Tool
The tools list is quite small and most of the are auxiliary:

  • Eraser tool. This tool simply erases the data from the layer, cleaning it up to the transparency. Few params can define eraser size, opacity and flow.
  • Move tool is designed to move the layer. It helps to position a drawing precisely.
  • Bucket tool fills the layers with some color. It’s added to fill the background layers or clear the layer with a single click (choose a transparent color).
  • Smoke tool is the heart of the app. It’s described in details a bit lower.

The main tool of the app is the “Smoke” tool, it can be used to render various graphics. The default settings defines colorful and smooth “rainbow” curves, however, it can be easily adjusted with few parameters:

  • Flow – colors may change slowly while you drawing. This slider controls the speed of that change. Move it to the left to avoid color changing.
  • Range – you define the main color using the color well in the toolbar. This slider defines how many “neighbor” colors Fumy can use for drawing. Fumy uses color circle (hue) to select neighbor colors.
  • Intensity – this parameter defines how bright is the trace of the points.
  • Density – Fumy draws using the set of dots. This parameters affects the level of filling the space between the dots. At the left position you draw a set of lines, while at the right position you draw the solid trace.
  • Fluency – this slider controls the movement of the points. Left position means chaos, right position means smoothness.
  • Gravity– the level of gravity of the mouse cursor. The more its value, the stronger is the gravity.
  • Quality– the level of renderer smoothing. Higher level takes more time to process, but the results look smoother.

Plus there are few switchers: “Type” toggles the renderer, it could be “Smooth”, “Network” and “Atlas”. The “Mode” switcher is designed to toggle wireframe mode and the “Map” can be used to make tiled pattern with “Tiled” option selected.

Here is an example of some possible brushes you can make with the Fumy app:

Layers & Blend Modes

Fumy Layers

The layers are supported in a usual for bitmap editors way: each layer is an independed “image”, blended with others with some rule. There are only three blend modes: “Add”, “Subtract” and “Normal”. The first one accumulates pixels of the top layer over the bottom one, the second mode Subtracts top layers from the bottom. The last mode is traditional alpha-blending of the top layer over the bottom one. Below you can see the results:
Blend Modes
The left image is made with default “Add” blendmode over a black background, in the middle is the “Subtract” mode over white background and the right image is Fumy icon loaded into the app and rendered with “Normal” mode.

The app supports a bunch of layers operations: you can add, remove layers, load layers from images (via the menu or simply by drag’n drop a file into the layers list or the canvas), adjust each layer blend mode and opacity, rename layers. You can also merge all the layers into a single one. Most of the operations are available through the “Layers” menu:

Layers Menu


The app supports own “.fumy” format for the documents, however, it can export merged images like PNG, TIFF and so on. You can save the whole image or an individual layer which is useful if you want to use a layer in some third-party editor as a layer.

Please, note: Fumy app uses “Add” blend mode by default, so, when you imprort a Fumy-saved PNG into the, lets say, PhotoShop, you must use “addition” blending there as well. Else you’ll get usual alpha-blending which will look a bit different.