Skip to content

Update RGC transformId in documentation #44

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
scottdyer wants to merge 2 commits into
base: main
Choose a base branch
from
+12 −9
Open

Update RGC transformId in documentation #44

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
92bfe51
Update Transform ID in RGC specification.
scottdyer Apr 18, 2026
0ea3eeb
Update transform ID of RGC and clarify versioning recommendations in …
scottdyer Jun 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 8 additions & 5 deletions docs/rgc/guides/rgc-implementation/index.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -66,16 +66,19 @@ Reference Implementation Specifications

### Versioning and Naming

The Reference Gamut Compression published in ACES 1.3 uses the following ACES
Transform ID and ACES User Name in the
[CTL](https://github.com/ampas/aces-core/blob/v1.3/transforms/ctl/lmt/LMT.Academy.GamutCompress.ctl):
The Reference Gamut Compression should use the ACES Transform ID and ACES User Name from the
reference CTL in the current ACES version.

In ACES 2.0, the Transform ID and User Name are:

```
<ACEStransformID>urn:ampas:aces:transformId:v1.5:LMT.Academy.ReferenceGamutCompress.a1.v1.0</ACEStransformID>
<ACESuserName>ACES 1.3 Look - Reference Gamut Compress</ACESuserName>
<ACEStransformID>urn:ampas:aces:transformId:v2.0:Look.Academy.ReferenceGamutCompress.a2.v1</ACEStransformID>
<ACESuserName>Reference Gamut Compress</ACESuserName>
```

!!! note
Though the URN changed since it was first introduced in v1.3, the transform math has not. Therefore, it is recommended to version up any AMFs that reference the old Transform ID to utilize the Transform ID from the current version, as you would for other equivalent Transform IDs from prior releases.

Implementers should only make the RGC available in the UI when their application
has the ACES version set to 1.3 or higher.

Expand Down
8 changes: 4 additions & 4 deletions docs/rgc/specification/index.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -173,15 +173,15 @@ $$
Tracking
----------------

The Reference Gamut Compression is defined as a [Look Transform (LMT) in CTL](https://github.com/ampas/aces-core/blob/v1.3/transforms/ctl/lmt/LMT.Academy.GamutCompress.ctl) and has the following ACES Transform ID:
The Reference Gamut Compression is defined as a Look Transform (LMT) in CTL and has the following ACES Transform ID:

```
<ACEStransformID>urn:ampas:aces:transformId:v1.5:LMT.Academy.GamutCompress.a1.3.0</ACEStransformID>
<ACEStransformID>urn:ampas:aces:transformId:v2.0:Look.Academy.ReferenceGamutCompress.a2.v1</ACEStransformID>
```

This is trackable via a lookTransform element in an AMF file. If the RCG is used in the viewing pipeline, the lookTransform will be listed in the associated AMF. If the AMF is accompanying rendered media, the applied flag should be used to track whether or not the RGC has been “baked in”.
This is trackable via a `lookTransform` element in an AMF file. If the RCG is used in the viewing pipeline, the `lookTransform` will be listed in the associated AMF. If the AMF is accompanying rendered media, the applied flag should be used to track whether or not the RGC has been “baked in”.

If using the RGC in a viewing pipeline, this lookTransform should appear directly after the IDT, first in the list of any LMTs, to make sure other operations benefit from the gamut compression.
If using the RGC in a viewing pipeline, this `lookTransform` should appear directly after the IDT, first in the list of any LMTs, to make sure other operations benefit from the gamut compression.

The Transform ID should be included in any exported AMFs, with the applied flag set as appropriate, and the description set to the ACESuserName to enable proper tracking. Currently, only the Reference (i.e. static) Gamut Compression is trackable via AMF.

Expand Down