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Character sets#

A character set turns the character LoRAs of a scene into one fused model pack and a preset that uses it. Fusing costs a few minutes once; after that every take in the scene runs at the speed of a plain preset, with all the characters baked in.

Scene settings with the character set card

Build a set#

  1. Open the scene settings and find the Character set (pack) card.
  2. Fill the default LoRA list of the scene. Add from character pulls a LoRA from the bank of a character; you can also pick any LoRA from the video LoRA library.
  3. Click Build and assign character set. Maystro fuses the LoRAs into the H3 pack, creates a preset named after the scene and its characters, and assigns it to the scene and to every shoot in it.

Building takes about 3 to 10 minutes and needs roughly 21 GB (pruned base) to 32 GB (full base) of free disk for the pack. A set whose LoRA list has not changed is reused, not rebuilt.

Pack base#

  • Reference-to-video (default) builds the set on the Ref2VA transformer: the shoots keep their reference images, and the reference plus the LoRA give the finest identity. When a pruned Ref2VA transformer is installed (the pruned bundle, or pruned base by local fold under Models → Video → Install), the set is built on it: a pack of about 21 GB instead of 32 and lower RAM use while rendering, at the same speed.
  • Text-only / start frame builds the same set on the Hailuo 3.0 transformer for shoots without a reference image: the character renders from the trigger word alone, and a shoot needs no start frame either.

The two are separate packs (about 21 to 32 GB each). The card shows which base the scene's current preset was built on; switching the base and building again assigns the other pack's preset.

  • Your own file: a custom preset that carries its own H3 transformer (a Comfy-layout bf16 single file, full or pruned) shows the same panel on the Models page, under the custom preset. Sets built there fuse the LoRAs into that file. Build int8 pack without LoRA converts the file to an int8 pack as it is, so it streams like the catalog packs (a pruned file gives a pack of about 21 GB). The derived preset keeps the custom preset's model and defaults.
  • Scene preset's own file: when the scene's preset is such a custom preset, or a set already built on one, the scene card offers that file as a third base and selects it by default. The set is fused into your file and the derived preset keeps the custom preset's model and defaults. Pick a catalog base to build the same set on the official transformer instead; the card names the base the scene's current preset was built on.

What you get#

  • Shoots in the scene render with the set preset by default. New shoots inherit it.
  • The LoRA list stays on the scene and its shoots as the definition of the set. When a shoot renders with the set preset, those LoRAs are not applied a second time: they are already fused into the pack.
  • Each character keeps their trained features across takes, including takes where they have no reference image.
  • The card shows what was expected, what was found and what was produced: the LoRA list, the pack it resolved to, and the preset name.

Changing the cast#

Edit the LoRA list and build again; the scene switches to the new preset.

LoRAs on a shoot#

The shoot panel has its own LoRA list. On LTX presets it is a normal per-shot LoRA. On MiniMax H3 it is not the way to use a character LoRA, and the panel says what the list does on the active preset:

  • On a character set preset the list is ignored: the set's LoRAs are already fused into the pack. The panel lists the fused LoRAs and marks any LoRA added to the shoot as not applied. Change the cast from the scene's character set card.
  • On the stock Ref2VA preset the LoRAs are fused into the model at load time on every job: slow, and heavy on system memory (it filled a 64 GB machine). A shoot with its own LoRAs also runs on the standard base even when the stock preset has been sped up. For anything beyond a test, build a character set instead.
  • A base file that is already an int8 pack cannot take per-job LoRAs; the runtime refuses the job with a message that points to character sets.

Packs on disk#

Packs are large (about 21 to 32 GB each), so Models → Character packs keeps a budget of them: when a new build pushes the count over the budget, the packs used least recently are deleted. A pack that a preset still references is never deleted this way, so the presets you assigned keep working.

If a pack is gone anyway (deleted by hand, or dropped before this rule existed), the preset picker marks its preset with character pack dropped, generating with it stops with the same message, and Models → Character packs → Dropped packs offers Rebuild: the pack is built again from the LoRA set the preset recorded, so the preset works again when the build finishes. On a GPU with int8 tensor cores it comes back as a fast int8 pack and the preset follows it. A hand-made preset that only points at a pack file records no LoRA set; rebuild that one from the scene's character set card.

Maystro also finds packs in the extra roots you added, for example the models folder of an earlier install. Such a pack is marked In added folder and works like any other: its presets render, and building the same LoRA set again reuses it instead of making a copy. Maystro only reads that folder, so it never deletes the pack there and does not count it against the budget. To remove it, delete its two files (pack_<id>.safetensors and pack_<id>.json) from that folder. New builds always go to the main models root.

Fast int8 packs#

On an NVIDIA GPU with int8 tensor cores (RTX 20 series and newer), new sets are built with the fast int8 kernel: the transformer's block layers run as int8 × int8 instead of int8 weights computed at bf16 speed, and the norms, rotary position embedding and residual adds around them run as fused kernels. Each denoising step takes about a third less time; a 15-second 1344×768 take with the default match reference canvas measured about 11 minutes instead of 17. The picture stays close to the standard pack: the same shots, actions and identity, with small differences in framing and fine detail.

Under the H3 presets in Models → Video → Presets and model assignments, each pack shows its kernel, Fast int8 or Standard int8. A standard pack that a preset uses offers Speed up: Maystro builds its fast twin from the same base and LoRA set (a few minutes, the same disk size) and then moves every preset that used the old pack onto it. The presets keep their names and settings, so the scenes and shoots that use them switch over with no other change. The old pack stays on disk until the pack budget drops it.

Fast packs are for rendering only; LoRA training keeps using the standard base.

Speeding up the stock preset#

The stock presets — MiniMax H3 — Referanslı (Ref2VA) and the text-to-video MiniMax H3 (Hailuo 3.0) — stream the standard int8 base, so they do not get the fast kernel by themselves. On a machine without a Vireo int8 pack of that base (every catalog install) the runtime loads the bf16 model file and quantises it to int8 on every cold load, so the first take after a restart starts a few minutes late; the steps then run at the standard int8 speed. Each stock preset's page under Models → Video → Presets and model assignments shows Stock preset speed with a Speed up button: Maystro builds a LoRA-free fast int8 pack from the same base (about 21 GB on a pruned base, 34 GB on the full one; a few minutes) and switches the stock preset to it in place. Every scene and shoot on the stock preset, screenplay imports included, then runs on the fast pack, with the fast load as well: a 124-frame 768×512 Ref2VA take with one face reference measured 74 seconds instead of 160 (steps of 4.3 s instead of 11.2 s).

  • A shoot with its own LoRAs keeps running on the standard base, where the LoRAs are applied as before; a character set is the fast way to use LoRAs.
  • Back to standard switches the preset back. The pack stays on disk until the pack budget drops it; deleting the pack also switches the preset back.
  • While the stock preset uses the pack, the budget never drops it. If its file disappears, the row says so: speed up again to rebuild it, or go back to standard.
  • The button appears only on GPUs that run the fast kernel.