AMVTools Bake ambient mask volumes and reflection probes for RDR2 / RedM interiors

AMVTools bakes the two things an RDR2 interior needs for believable ambient lighting: the ambient mask volume that decides how much sky every part of a room sees, and the reflection probe cubemaps. You build the zone in Blender, fit it to your geometry, and the add-on writes the game-ready files itself — the volume DDS with its XML, and the converted cubemap sets. Doors are a zone type of their own, so one interior can carry as many volumes as it has doors. There is no lighting setup step, because visibility is purely geometric: only the shape of the room and what occludes it matter.

AMVTools costs $10. The store also carries the same add-on at $20 and $30. All three contain exactly the same files: nothing extra, nothing unlocked, no separate build, no different
support. They are there for anyone who wants to give more for the same thing.

An older version is still free on GitHub — an outdated build without the current zone workflow, not maintained and not a full alternative.

$10 — the add-on, every feature, all future updates
$20 and $30 — identical files, just more support for development
Free GitHub build — old and unsupported, kept for reference only
Same setup either way — Blender alone for volumes and doors, plus texconv for reflection export

Buy whichever one you feel like. There is no difference in what you get.

Ambient Mask Volumes

Room volumes — bake a full ambient visibility volume for any interior straight from your Blender geometry
Doors — a door is its own zone, baked with the door preset already applied to its XML
Bounds from selection — select the opposite corners of the room in Edit Mode and the zone follows
Repeatable door identity — rebaking the same door updates its existing volume instead of creating a duplicate
Per-zone quality — interval, offset, smoothing and ray count, so one busy room can be finer than the rest of the interior
Safe to re-run — a cancelled or failed bake leaves your previous export untouched

Reflection Probes

Cubemap baking — the full probe set is rendered from your interior and converted to the game's cubemap formats
Four resolutions from one bake — 1024, 512, 256 and 128, ready for the XML to reference
Denoised alpha — the sky occlusion channel gets an edge-preserving pass that removes grain without eating real edges
Non-destructive — runs in a temporary scene and keeps your World, materials, compositor and GPU preferences

Fixing Individual Probes

Display Probes — preview spheres show exactly where the bake samples
Affected probes only — highlight or show only the probes that reach geometry, so you fix the handful that matter
Manual corrections — move the spheres you care about, save, and they are merged back into the grid
Protected — the bake refuses to run on stale manual positions instead of silently using them

Checked Before It Writes

Check Project — validates every zone without changing a single setting, separating errors from warnings
Bake All — the whole interior and door queue is validated before the first file is written
Reports — each bake writes a JSON report with the grid, timings and relocation counters
Skipping objects — hide a helper mesh from the bake with a collection prefix or one custom property, without hiding it from your renders

How It Works

Set up a zone per room, fit its bounds to the geometry and pick an interval — the distance between samples. The bake fires rays from the centre of every cell in that lattice and counts how much sky each one sees in six directions, which is exactly the ambient cube the game blends at runtime. Those numbers become two DDS files with their XML, placed in the world from the interior's own location and rotation. Work coarse first, look at the result in game, and refine only where a transition is actually visible.

Installation

Drop the zip into Blender through Edit > Preferences > Add-ons > Install from Disk, enable AMVTools and open the AMV tab in the 3D viewport sidebar. Volume and door export works right away; reflection export additionally needs Microsoft texconv, which you download once and point the add-on at. Done.

Requirements

Blender 4.0 or newer
Microsoft texconv from DirectXTex for reflection export (not bundled)