Best local MiniMax character swap workflow: SAM3 mask + color inversion, ~2.5 min on RTX 4090
Pleasant-Living-3702 · reddit · 2026-10-02
A Reddit user open-sourced a simplified local ComfyUI workflow for MiniMax character swapping, calling it the best local method available.
How it works
- SAM3 selects the character/area to change; the selected area's colors are inverted before generation, which helps MiniMax replace subjects more consistently
- The source video drives mouth/body motion and scene; a reference image drives the replacement's appearance
Performance: RTX 4090 (24GB VRAM) + 32GB DDR5, 3-second video at 0.8 MP in about 2 min 30 sec
Three modes (switched in the green settings node)
- Character replacement / video inpainting: swap characters or edit shirt/hair color, objects
- Reference-to-video generation (experimental)
- First-to-last frame transitions (experimental)
Useful features
- Save characters: store a reference image with a detailed character description for reuse across videos
- Trim the source video inside the workflow, no external editor needed
- Masking options: SAM3 by description, rectangle, or no mask (full frame re-render)
Starter settings: the example uses a Fixed seed for reproducibility (switch to Randomize to explore); start at 0.8 MP, try 1.0 MP for more resolution. Nothing is perfect — expect multiple attempts, and matching seeds doesn't guarantee identical results across setups.
More from coding & agent
- Snorkel AI lands five NeurIPS papers; hardest long-horizon agent tasks see <1% pass rate — ajratner · 2026-10-02
- cronstable: an open-source job scheduler with a built-in MCP server for agent-driven triage — ptweezy · 2026-10-02
- What happens when four AI agents update the same file? Testing Git worktrees vs AgentWS — pilver7 · 2026-10-02
- AREX-2: 27B reflective agent scores 81.8 on MLE-bench Lite via long-horizon self-improvement — _akhaliq · 2026-10-02
- Claude Given 12 Hours Autonomously Produced The Clodyssey — FinanceYF5 · 2026-10-02
- Hebbrix Launches Hosted MCP Memory Endpoint, Warns of Write-to-Searchable Gap — Separate_Sand8265 · 2026-10-02