SolarRenderer turns grey-box, skeleton or sketch video into finished shots with MiniMax H3
SolarRenderer is a pair of open LoRAs for MiniMax H3 that renders a structure video, such as a game-engine grey box, a skeleton or depth pass, or a pencil storyboard, into finished video in four sampling steps. The first frame and the prompt set the look, so the same blockout can come out photoreal, anime, pixel art or ink.
What it does
You give it a structure video (24 fps, at least 158 frames, 1344×768 landscape or 768×1344 portrait), an optional first frame in the look you want, and a prompt that names the structure. There's no separate branch or condition label per input type: it was trained on grey boxes, semantic maps, object masks with skeletons, SMPL body meshes and near-field depth, and the authors show it also handling pencil storyboards, point clouds, voxels, wireframes and a child's crayon drawing it never saw in training.
A four-step LoRA makes sampling 12.3× faster than 50 steps, and a block-causal pair of the LoRAs (the --causal option) streams the clip block by block, so each block can be shown as soon as it's done.
Results and limits
On one GPU, the authors report about 4 minutes of encoding and about 3.5 minutes of sampling for a 158-frame clip. They also released an open benchmark of 208 hard cases and 53 held-out clips, with the scoring code, their renders and every judge verdict, plus the 30,597-clip training set. These are the authors' own figures.
Worth knowing
You need the full MiniMax H3 weights (about 135 GB) plus about 8 GB of LoRAs, and it runs from Python scripts; the README doesn't mention a ComfyUI node. Prompts follow a trained six-part form (subject definitions, summary, retention analysis, a 350–500 word description, soundscape, music), and the repo ships an agent skill so a coding agent like Codex or Claude Code can write it for you. The code is Apache 2.0, but the weights fall under the MiniMax H3 Community License: Users in the EU, UK, US and South Korea need to request a license from MiniMax via the H3 License Request Form (platform.minimax.io/h3-license) before use.
Try it yourself
python scripts/render.py --h3 ./MiniMax-H3 --control weights/solarrenderer_control_lora.safetensors --fewstep weights/solarrenderer_4step_lora.safetensors --structure [your grey-box render].mp4 --first [a first frame in your look].png --prompt prompt.txt --out render.mp4 --seed 0