kicad2msla/UVtools/Readme.md

UVtools PCB Exposure CLI — Build & Usage Guide

This guide covers building a wrapper for theUVtoolsCmd, for headless Gerber → .pm4n (or any slicer format) conversion on Ubuntu.

Note: The UVtools maintainer is implementing an official equivalent via the generic run command and a new FileArray reflection property (-p FileArray=file.gbr). Once that ships in a release (issue 1127), you can switch to pcb-expose-official.sh and skip the patch/compile steps entirely — see Option B below.

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Option A: Patched local build (pcb-expose command)

1. Install .NET SDK

sudo snap install dotnet
export DOTNET_ROOT=/var/snap/dotnet/common/dotnet
dotnet --version

Add the export line to your ~/.bashrc so it persists across shells:

echo 'export DOTNET_ROOT=/var/snap/dotnet/common/dotnet' >> ~/.bashrc

2. Clone the repo

cd ~/proj
git clone --depth 1 https://github.com/sn4k3/UVtools.git
cd UVtools

3. Apply the patch

Copy pcb-expose.patch into the repo root, then:

git apply ../kicad2msla/UVtools/pcb-expose.patch

This does two things:

• Adds UVtools.Cmd/Symbols/PcbExposeCommand.cs (new pcb-expose subcommand)
• Registers it in UVtools.Cmd/Program.cs

Verify it applied cleanly:

git add .
git status
#   modified:   UVtools.Cmd/Program.cs
#   new file:   UVtools.Cmd/Symbols/PcbExposeCommand.cs

4. Restore & build

dotnet restore

dotnet publish UVtools.Cmd/UVtools.Cmd.csproj \
    -c Release \
    -r linux-x64 \
    --self-contained false \
    -o ./publish/

5. Copy the OpenCV native library

The published output doesn't include libcvextern.so — copy it from the repo:

cp build/platforms/linux-x64/libcvextern.so ./publish/

6. Test it

./publish/UVtoolsCmd pcb-expose \
    ~/proj/kicad2msla/Dummy.pm4n \
    ~/proj/kicad2msla/gerbers/Flow_Controller_Panel-Front.gtl \
    --invert \
    --mirror \
    --exposure 120 \
    --output ~/proj/kicad2msla/Flow_Controller_Panel-Front.pm4n

7. Install the wrapper

Copy pcb-expose-patched.sh somewhere on your $PATH, e.g.:

# Copy the script
cp ~/proj/kicad2msla/UVtools/pcb-expose-patched.sh ~/.local/bin
# Make it executable
chmod +x ~/.local/bin/pcb-expose-patched.sh
# Create a symlink
ln -s ~/.local/bin/pcb-expose-patched.sh ~/.local/bin/pcb-expose.sh

By default the wrapper looks for the build at ~/proj/UVtools/publish/UVtoolsCmd. If yours is elsewhere, either edit the UVTOOLSCMD variable at the top of the script, or set it as an environment variable each time:

export UVTOOLSCMD=~/proj/UVtools/publish/UVtoolsCmd

8. Usage

pcb-expose.sh ~/proj/kicad2msla/Dummy.pm4n \
    ~/proj/kicad2msla/gerbers/Flow_Controller_Panel-Front.gtl \
    --invert --mirror --exposure 120 \
    --output ~/proj/kicad2msla/Flow_Controller_Panel-Front.pm4n

Multiple files / per-file polarity inversion / merging into one layer:

pcb-expose.sh Dummy.pm4n \
    Board-F.Cu.gtl Board-B.Cu.gtl \
    --merge --invert-polarity --mirror --exposure 120 \
    --output Board-combined.pm4n

---

Option B: Official release (no compiling required)

Once the maintainer's FileArray property ships in an official UVtools release:

1. Download & install the release

Grab the Linux release from the UVtools releases page and extract it, e.g. to ~/UVtools/. libcvextern.so is bundled in official releases, so no extra steps are needed there.

2. Install the wrapper

# Copy the script
cp ~/proj/kicad2msla/UVtools/pcb-expose-official.sh ~/.local/bin
# Make it executable
chmod +x ~/.local/bin/pcb-expose-official.sh
# Create a symlink
ln -s ~/.local/bin/pcb-expose-official.sh ~/.local/bin/pcb-expose.sh

By default it looks for ~/UVtools/UVtoolsCmd. Override with:

export UVTOOLSCMD=~/UVtools/UVtoolsCmd

3. Usage

Same interface as Option A (minus --invert-polarity, which the official FileArray property doesn't support per-file):

pcb-expose.sh ~/proj/kicad2msla/Dummy.pm4n \
    ~/proj/kicad2msla/gerbers/Flow_Controller_Panel-Front.gtl \
    --invert --mirror --exposure 120 \
    --output ~/proj/kicad2msla/Flow_Controller_Panel-Front.pm4n

Internally this runs:

UVtoolsCmd run Dummy.pm4n PCBExposure \
    -p FileArray=Board-F.Cu.gtl \
    -p InvertColor=true \
    -p Mirror=true \
    -p ExposureTime=120 \
    --output Board-F.Cu.pm4n

---

Files in this bundle

File	Purpose
pcb-expose.patch	git apply-able patch adding the pcb-expose command (Option A)
pcb-expose-patched.sh	Wrapper for the patched local build
pcb-expose-official.sh	Wrapper for the official release using run + FileArray