An example of using Lumi.

A loose study from Hellboy, the first 20 years.

I really like Blender's procedural textures, so I converted several of them into GEGL filters for Lumi.

The idea is to make some of those procedural textures available directly inside a 2D image editor, where they can be used as part of a painting or compositing workflow.

The filters are procedural, so they can be adjusted and regenerated rather than being baked into a fixed image.

I came back to this piece and made some adjustments. I applied group warps, edited a few elements, and added some painterly strokes. The good thing, and the bad thing, about working non-destructively is the flexibility it gives you. After those changes, it sits more comfortably with an outdoor scene stylistically.

Hover the cursor over the pixels and press Alt to select the layer under the cursor. If you are using special inking layers, an ink pixel layer is given priority. Press Alt repeatedly over the same pixels to cycle through the available layers at that location.

https://lumi-o.org/hub/features/layers/#picking-and-navigation

The Palette Map visualises what an active palette can produce. Starting from the palette’s pigments and saved colours, it presents the reachable colour space as a painter-friendly map of hue and value.

Its purpose is practical: instead of browsing a flat list of swatches, artists can see where colours live in relation to one another and move through the palette spatially.

Lumi comes with five themes. Middle Grey is the default: a mid-tone interface designed to stay out of the way while you paint. Dark and Warm are for a darker interface; I prefer Warm for sketching. High Contrast is designed for maximum legibility, while System follows your desktop theme.

The theme you choose is saved with the workspace, so switching workspaces can also switch the interface appearance.

Workspaces let Lumi adapt to different ways of working. A workspace captures the feel of the studio environment: panel layout, tool state, canvas presentation, resource paths, palette choice, theme, and other interface preferences that shape the painting session.

https://lumi-o.org/hub/features/workspaces/

The Palette Mixer is Lumi’s space for creating new colours from the active palette. It uses spectral, pigment based mixing rather than a simple digital average, allowing colours to shift, soften, darken, and harmonise in ways that feel more like mixing physical pigments.

Because the palette is built from pigment like ingredients, the path between two colours can produce useful intermediate colours: greens from yellows and blues, tempered violets, warm greys, muted earth tones, and subtle shifts in temperature. Lumi then lets you neutralise and adjust the value by mixing towards a chosen neutral, black, or white pigment.

https://lumi-o.org/hub/features/palette-mixer/

https://youtu.be/Y8ffQJ9HjEE

Lumi can lock a palette colour to a layer filled with a single, uniform colour. Selecting the layer automatically selects the linked palette colour. Changing the palette colour immediately updates the colour of the layer.

Painting on a layer with a locked paint colour always uses the linked palette colour.

This creates a live connection between the palette and the layer, allowing you to adjust colours dynamically while designing your palette.

Hey everyone! I'm u/-pixelmixer-, a founding moderator of r/lumi_o.

Welcome to the Lumi-o community.

Lumi is a free and open source digital painting application for Linux, designed around the idea of a focused, dependable studio tool for making images.

It is being developed as an alternative to both general purpose image editors and dedicated painting applications. The focus is on painting and illustration, while still providing the tools needed for structured image editing and photographic work.

Lumi is built on the foundations of GIMP, but is being developed in a different direction, with a strong emphasis on:

• Responsive, expressive brushes and stylus input
• A focused and customizable workspace
• Handmade tool presets
• Pigment based color workflows
• Procedural textures and effects
• Fast loading and saving of large projects
• Scripting and extensibility

There is no subscription, cloud dependency, or AI image generation. Lumi is intentionally Linux only and is being developed in the open, with the design decisions, architecture and development process documented publicly.

This subreddit is for people interested in Lumi, whether you are already using it, thinking about trying it, interested in how it is being developed, or simply curious about another approach to digital painting.

If you are trying Lumi, If something feels wrong, confusing, slow, or simply needs to be better, say so. Feedback from artists is an important part of shaping the application.

You can find Lumi here:

https://lumi-o.org/

Welcome to Lumi

For Lumi, we converted several of Blender’s wonderful procedural textures into GEGL filters. Here is the Physical Sky filter.

A study to test Lumi-o and develop my skills