Download SDK for your OS and move bella_scene_sdk into your workdir. On Windows rename unzipped folder by removing version ie bella_engine_sdk-24.6.0 -> bella_scene_sdk https://bellarender.com/builds/

workdir/
├── bella_scene_sdk/
├── libplist/
├── lzfse/
├── opengametools/
└── vmax2bella/

MacOS

mkdir workdir
git clone https://github.com/lzfse/lzfse
mkdir -p lzfse/build
cd lzfse/build
/Applications/CMake.app/Contents/bin/cmake -DCMAKE_OSX_ARCHITECTURES="x86_64;arm64" ..
make -j4
cd ../..
mkdir homebrew
curl -L https://github.com/Homebrew/brew/tarball/master | tar xz --strip-components 1 -C homebrew
eval "$(homebrew/bin/brew shellenv)"
brew update --force --quiet
brew install libtool autoconf automake
git clone https://github.com/oomer/libplist
cd libplist
./autogen.sh --prefix=$PWD/install --without-cython
make -j4
install_name_tool -id @rpath/libplist-2.0.4.dylib src/.libs/libplist-2.0.4.dylib
cd ..
git clone https://github.com/jpaver/opengametools.git
git clone https://github.com/oomer/vmax2bella.git
cd vmax2bella
make

Linux [NOT READY]

mkdir workdir
git clone https://github.com/lzfse/lzfse
mkdir lzfse/build
cd lzfse/build
cmake ..
make -j4
cd ../..
git clone https://github.com/oomer/libplist
cd libplist
./autogen.sh --prefix=$PWD/install --without-cython
make -j4
cd ..
git clone https://github.com/jpaver/opengametools.git
git clone https://github.com/oomer/vmax2bella.git
cd vmax2bella
make

Windows [NOT READY]

Install Visual Studio Community 2022
Add Desktop development with C++ workload
Launch x64 Native tools Command Prompt for VS2022

mkdir workdir
git clone https://github.com/lzfse/lzfse
mkdir -p lzfse/build
cd lzfse/build
cmake ..
msbuild lzfse.vcxproj /p:Configuration=release /p:Platform=x64 /p:PlatformToolset=v143
cd ../..
git clone https://github.com/oomer/libplist
git clone https://github.com/jpaver/opengametools.git
git clone https://github.com/oomer/vmax2bella.git
cd libplist
msbuild libplist.vcxproj /p:Configuration=release /p:Platform=x64 /p:PlatformToolset=v143
cd ..
cd vmax2bella
msbuild vmax2bella.vcxproj /p:Configuration=release /p:Platform=x64 /p:PlatformToolset=v143