rmdlconv (R5Flowstate / S21)

Converts Source / Respawn studio models between versions. This fork is the S21-bridge converter: it can emit mdl_ v17 for the S21 client and v10 / v54 for the S3 dedicated server. Upstream rmdlconv only targeted S3 (v54 / rmdl v10).

Upstream: r-ex/rmdlconv.

What this fork adds

• v19.1 / v16 -> v17 compact client path (-targetversion 17): keeps the modern on-disk shape, shrinks seqdesc/animdesc to S21 sizes.
• v12.2 (S10) -> v17 client rebuild (-v122 -targetversion 17).
• v8 -> v17 upgrade (animation gate flag).
• Collision: preserve unk4_v54 (per-query-class part map, including -1 sentinels), modern->legacy surface-prop remap, bone followers, phySize, 16-byte bvhOffset alignment.
• Per-LOD switch distances carried through instead of zero-filled.
• v17 placeholder sequences match S21 refs (paramindex -1, flags 0x80000).

Legacy S3 paths (Portal 2 v49 / TF2 v53 -> v54) remain.

Usage

Drag-and-drop a .mdl / .rmdl, or:

rmdlconv.exe -convertmodel <file-or-dir> -targetversion 17 -outputdir <out>

• -targetversion 17 — S21 client (v17)
• -targetversion 54 or 10 — S3 dedi (v54 / rmdl v10)
• -v122 — treat input as v12.2
• -nopause — close the console when done
• -outputdir — output directory

Animation in the model file is limited; S21 animated props go through R5-AnimConv (-o 21) and RePak aseq/arig.

Building

Open rmdlconv.sln and build x64 Release.