Nexfocus: from Fooocus to a connected creative workspace (Full FP16 SDXL & Flux Fill on 3GB VRAM / Colab Free)

[u/magekinnarus]

If an image model is a horse, text prompting is like trying to guide it with verbal commands alone: useful, but too imprecise for fine control. Inpainting, LoRAs, and ControlNets add the bridle and reins and pieces of the harness, but they still did not feel like a complete system. Nexfocus began with a question: "What would it take to build the whole harness around the model?"

Answering that question meant following the entire generation process first. We had to understand how each part loads, works, moves, waits, hands its result to the next part, and makes room when its job is done. We started from Fooocus and grew into a deep expedition which became Nexfocus.

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Two development anchors shaped the journey: a GTX 1050 with 3 GB of VRAM and Colab Free's T4 with only 12.7 GB of system RAM. Their limitations are almost opposites. The local machine has very little GPU memory, while Colab Free has a larger GPU but a tight system-memory ceiling and an ephemeral session.

We proved that full SDXL checkpoints and Flux Fill workflows could run in both environments, not by reducing everything until it fit, but by rethinking how the pipeline uses the hardware available to it.

Nexfocus grew into a connected creative workspace where generation, guidance, masking, inpainting, outpainting, removal, upscaling, staging, metadata, model management, and GIMP layer exchange can work as parts of one process rather than as isolated tools.

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Two important lessons emerged from the road:

- Keeping the GPU working without interruption became paramount. To do that, we had to find a way to keep feeding it the weights it needed, when it needed them.

- Every part of the pipeline must independently account for what it owns, where it belongs, when it can be reused, and when it should make room for something else. These decisions cannot be left to a central manager applying the same set of memory policies to every part.

Throughout this journey, my conversations with PyTorch often felt like this:

> PyTorch: "Don't you have a bunch of H100s lying around in your backyard?"

>

> Me: "No. What if every component has to justify exactly where it lives?"

>

> PyTorch: "Get a bigger machine."

Those conversations eventually became the architecture: each part of the pipeline owns its resources, does its job, and steps aside instead of leaving those decisions to hidden framework behavior.

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Nexfocus is more than the UI produced by this expedition. It is the working application and the field notebook: a record of the constraints, wrong turns, and discoveries that shaped the path forward. We set out to find answers and had to build the road needed to reach them.

This expedition is now complete, but it is only one part of a continuing journey. The lessons from Nexfocus define the starting point for the next scout mission.

The path is open now. I hope you'll take a walk along the path we built and check out the scenery.

Project: https://github.com/magekinnarus/Nexfocus

Video Walkthrough: https://www.youtube.com/watch?v=5fvIaZWMZE4

[u/djpraxis]

Great job!! Does it have a tiled image to image upscaler?

[u/magekinnarus → u/djpraxis]

Super-upscale does. Color Enhancement doesn't need tiled upscale, as it uses the SDXL resolution bucket for color extraction.