From a0d67ee447aaa87bf4629da95fc80a659d821cd0 Mon Sep 17 00:00:00 2001
From: Igor Altsybeev <Igor.Altsybeev@cern.ch>
Date: Tue, 17 Mar 2026 14:26:22 +0100
Subject: [PATCH] update of readme for FT3 and ALICE3

---
 Detectors/Upgrades/ALICE3/FT3/README.md | 20 ++++++++++++++++++++
 Detectors/Upgrades/ALICE3/README.md     | 15 +++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/Detectors/Upgrades/ALICE3/FT3/README.md b/Detectors/Upgrades/ALICE3/FT3/README.md
index 71cb7a6e63bb9..34a6782a2b0c2 100644
--- a/Detectors/Upgrades/ALICE3/FT3/README.md
+++ b/Detectors/Upgrades/ALICE3/FT3/README.md
@@ -6,5 +6,25 @@
 
 This is top page for the FT3 detector documentation.
 
+## Specific detector setup
+
+
+Configuration of the endcap disks can be done by setting values for the `FT3Base.layoutFT3` configurable,
+the available options are presented in the following Table:
+
+| Option                 | Comments                                                                                                          |
+| ---------------------- | ----------------------------------------------------------------------------------------------------------------- |
+| `kSegmented` (default) | Currently, only OT disks have realistic implementation, for ML - simple trapezoids                                |
+| `kTrapezoidal`         | Simple trapezoisal disks (in both ML and OT), with `FT3Base.nTrapezoidalSegments=32`                              |
+| `kCylindrical`         | Simplest possible disks as TGeoTubes (ML and OT), bad for ACTS (wrong digi due to polar coorinates on disk sides) |
+
+[ [Link to definitions](./base/include/FT3Base/FT3BaseParam.h) ]
+
+For example, a geometry with the endcaps-only can be obtained by
+```bash
+o2-sim-serial-run5 -n 1 -g pythia8hi -m FT3 \
+  --configKeyValues "FT3Base.layoutFT3=kTrapezoidal"
+```
+
 <!-- doxy
 /doxy -->
diff --git a/Detectors/Upgrades/ALICE3/README.md b/Detectors/Upgrades/ALICE3/README.md
index 44a478b592882..6ff034facb546 100644
--- a/Detectors/Upgrades/ALICE3/README.md
+++ b/Detectors/Upgrades/ALICE3/README.md
@@ -69,8 +69,23 @@ Configurables for various sub-detectors are presented in the following Table:
 | Available options | Link to options                                                  |
 | ----------------- | ---------------------------------------------------------------- |
 | TRK               | [Link to TRK options](./TRK/README.md#specific-detector-setup)   |
+| FT3               | [Link to FT3 options](./FT3/README.md#specific-detector-setup)   |
 | TOF               | [Link to TOF options](./IOTOF/README.md#specific-detector-setup) |
 
+Example O2 command to create a geometry with **segmented layers for TRK (expect for VD), FT3 and TOF:**
+
+```bash
+o2-sim-serial-run5 -n 1 -g pythia8hi -m A3IP TRK FT3 TF3 \
+--configKeyValues "TRKBase.layoutVD=kIRISFullCyl;TRKBase.layoutMLOT=kSegmented;FT3Base.layoutFT3=kSegmented;IOTOFBase.segmentedInnerTOF=true;IOTOFBase.segmentedOuterTOF=true"
+```
+
+Example O2 command to create a geometry with **simple (non-segmented) layers for TRK, FT3 and TOF**:
+
+```bash
+o2-sim-serial-run5 -n 1 -g pythia8hi -m A3IP TRK FT3 TF3 \
+--configKeyValues "TRKBase.layoutVD=kIRISFullCyl;TRKBase.layoutMLOT=kCylindrical;FT3Base.layoutFT3=kTrapezoidal;IOTOFBase.segmentedInnerTOF=false;IOTOFBase.segmentedOuterTOF=false"
+```
+
 ### Output of the simulation
 The simulation will produce a `o2sim_Hits<DetID>.root` file with a tree with the hits related to that detector.