01 welcome and launch

Welcome and launch

This page covers starting FractalFlow as a GUI app, the Welcome to FractalFlow window, and the First-run setup checks that run before the main tabs appear.

First-run setup with installed dependencies and detected renderers.

What you need

• Windows 10 version 1809 or later, or Windows 11, 64-bit.
• A Direct3D 12 GPU for the in-process HLSL renderer. CPU fallback covers the formula catalog when no GPU is available, but can be substantially slower.
• WebView2 Evergreen (Microsoft Edge WebView2 Runtime) for Psychedelia Live, Animation Lab / Generator Lab, and Shader Lab.
• Video encoding uses ffmpeg.exe. FractalFlow looks beside the executable, on PATH, or can install ffmpeg on demand the first time encoding is requested.

The portable test build is a single self-contained Fractalflow.exe. You do not need a separate .NET install to run that published file. WebView2 Evergreen is a shared Microsoft system runtime, not a second FractalFlow file.

Starting the GUI

Double-click Fractalflow.exe, or run it with no subcommand:

.\Fractalflow.exe

With no recognized CLI verb, the process opens the WPF app. If the first argument is a verb such as render, catalog, or api, FractalFlow stays in the console and does not open the GUI. See CLI and API.

Portable layout next to the exe:

Folder / file	Role
Fractalflow.exe	The app
ffmpeg.exe	Optional companion encoder (if you kept one beside the exe)
data\	Library database, settings, logs, thumbnails, drafts
output\	Rendered videos, PNG sequences, Clip Studio exports

Optional environment:

• FRACTALFLOW_DATA_DIR — override the data folder.
• FRACTALFLOW_OUTPUT_DIR — override the output folder.
• FRACTALFLOW_ENABLE_WARMUP=1 — after launch, pre-render a small set of template and hearted-seed thumbnails. Off by default so startup stays responsive.

Welcome to FractalFlow (first-run setup)

On the first launch, or any launch where first-run was not completed, FractalFlow shows a window titled Welcome to FractalFlow. The header reads FractalFlow with the subtitle First-run setup.

Closing this window without Continue to FractalFlow does not mark setup complete. The wizard will appear again next launch.

Dependencies

ffmpeg

Shows whether a usable ffmpeg binary was found. Video assembly (MP4 / MKV / Clip Studio exports) needs it. If it is missing, you can still explore and preview; encoding is requested later and can install ffmpeg on demand.

WebView2 Evergreen

Shows whether Microsoft Edge WebView2 Runtime is installed. The helper text on this screen is:

WebView2 Evergreen powers Psychedelia Live, Animation Lab, and Shader Lab. It is a shared Microsoft system runtime, not a second FractalFlow application file.

If it is missing, the Get from Microsoft button appears. Click it, complete Microsoft’s installer, restart FractalFlow, then click Re-check.

You cannot skip this forever if you want the Videos procedural workspaces. Native Explore / Compose / Render still run without it.

Available renderers

This list is a live probe of backends FractalFlow registered at startup. Typical rows:

• In-process HLSL Direct3D 12 compute renderer (the main GPU path).
• CPU (all formulas, slower) fallback renderer (uses the CPU workers budget from Resources). GPU depth-lighting effects are not reproduced by its separate CPU lighting rig; use HLSL when those effects matter.

Each row shows a mark, display name, family, and status. A banner may appear if a renderer is missing or degraded.

The body text on this screen:

The Welcome helper paragraph below contains older, conservative CPU-coverage wording. The current renderer list and warnings are authoritative; formula coverage does not imply identical lighting.

FractalFlow ships with the in-process HLSL Direct3D 12 renderer + a CPU fallback. The HLSL renderer auto-detects DX12-capable GPUs and uses the enabled adapters from Resources. The CPU renderer covers a subset of formula families and uses a configurable thread budget.

Footer buttons

Button	What it does
Re-check	Re-runs ffmpeg, WebView2, and renderer probes without leaving the window.
Continue to FractalFlow	Enabled when setup can proceed. Marks first-run complete and opens the main window.

See the First-run setup with installed dependencies and detected renderers screenshot.

After Continue to FractalFlow

The Welcome to FractalFlow window closes. The main window titled FractalFlow opens, with the subtitle — HLSL fractal renderer and the six tabs. First stop is usually Explore. Before a long render, visit Resources and confirm GPUs, CPU workers, GPU concurrency, Final output, and Keep PNG frame sequence.

Later launches

Once first-run is complete, double-clicking Fractalflow.exe goes straight to the main window. First-run does not reappear unless you reset settings (see Files and recovery).