ModelMergeCosmos14B_motorway_edition

Cosmos is NVIDIA's video-model family, and the 14B variant is the big one. ModelMergeCosmos14B is ComfyUI's per-block merge node for that specific architecture - 36 transformer blocks plus a distinctive embedder set - and this is its Motorway-ed clone. The model-specific merge nodes exist because each transformer layout has its own block names, and Cosmos's are different enough that a generic merge can't address them by name.

The block layout

• pos_embedder and extra_pos_embedder - positional embeddings for the spatial and temporal structure. Video models lean on these hard; if your two checkpoints differ in training resolutions or frame counts, these are the first regions to treat carefully.
• x_embedder - the latent input projection.
• t_embedder - timestep conditioning.
• affline_norm - (spelled that way in the node, it's a legacy "affine" norm) the normalization for the conditioning path.
• blocks.block0–blocks.block35 - the 36 main transformer blocks. Lower blocks handle coarse structure and motion; the higher ones carry fine temporal detail.
• final_layer - the output projection back to latent space.

Every ratio defaults to 1.0, and the family gotcha applies without exception: untouched, the merge returns model2. Set a base blend across all the floats first, then push regions - embedders for conditioning behavior, late blocks for detail.

Worth knowing before you sink time in: Cosmos models (including the Predict2 generation) were primarily pitched at world-model research and robotics, not at the image/video-checkpoint merge culture. If you're merging Cosmos checkpoints, you're on the frontier, which means thinner community recipe lore - lean on your own sampling, and keep expectations modest on first tries.

The inputs

• INPUT_model1_key (default model1) and INPUT_model2_key (default model2) - the two Cosmos 14B models.
• The block ratios, each 0.0–1.0, step 0.01, default 1.0.
• OUTPUT_MODEL_key (default MODEL) - where the merged model lands.

The wrapper keeps every ratio as a widget, turns the models into key strings, and keyed-writes the result. Runtime behavior matches stock ModelMergeCosmos14B.

Install

One install for the whole pack. ComfyUI Manager, search "ComfyUI_agilly1989_motorway", or:

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

Restart ComfyUI. No requirements.txt, no model downloads.

Troubleshooting

• Result is pure model2? All ratios default to 1.0 - set a base blend first.
• Use the 14B node for 14B checkpoints and the 7B node for 7B - the block counts differ (36 vs 28), so cross-using them won't blend anything meaningful.
• Merge Cosmos with Cosmos only. LTX, Mochi, and Flux each have their own block layouts; the numbers won't map.
• 'MotorwayClass' object has no attribute 'hash_' = a model key isn't in the Motorway; check the loaders ran and the key spelling matches (case-sensitive).
• Pack caveats: BETA, and the newest published version (1.1.7) disabled clone generation, so on a fresh install these _motorway_edition nodes may be missing from the menu. They're present in the 1.1.0–1.1.6 builds comfy.icu indexed.