diff --git a/conda-recipe/conda_build_config.yaml b/conda-recipe/conda_build_config.yaml
index 4f3c872..7ce68f3 100644
--- a/conda-recipe/conda_build_config.yaml
+++ b/conda-recipe/conda_build_config.yaml
@@ -1,3 +1,7 @@
+# Channels to use for build dependencies
+channel_sources:
+  - conda-forge,nvidia
+
 # CUDA versions to build against
 cuda_compiler_version:
   - "12.6"
diff --git a/run_gpu_test.bat b/run_gpu_test.bat
new file mode 100644
index 0000000..8b6563c
--- /dev/null
+++ b/run_gpu_test.bat
@@ -0,0 +1,332 @@
+@echo off
+setlocal enabledelayedexpansion
+
+:: GPU Test Script for Windows
+:: Equivalent to .github/workflows/gpu-test.yml
+
+echo ============================================
+echo RTXpy GPU Test - Windows Local Runner
+echo ============================================
+echo.
+
+:: Configuration
+set OPTIX_DIR=C:\optix
+set OPTIX_VERSION=v7.7.0
+
+:: Get the directory where this script is located
+set SCRIPT_DIR=%~dp0
+cd /d "%SCRIPT_DIR%"
+
+:: Step 1: Verify GPU
+echo [1/10] Verifying NVIDIA GPU...
+echo ----------------------------------------
+nvidia-smi >nul 2>&1
+if errorlevel 1 (
+    echo ERROR: nvidia-smi not found. Please install NVIDIA drivers.
+    exit /b 1
+)
+nvidia-smi
+echo.
+echo OptiX 7.7 requires driver 530.41+
+echo OptiX 8.0 requires driver 535+
+echo OptiX 9.1 requires driver 590+
+echo.
+
+:: Step 2: Verify CUDA Toolkit
+echo [2/10] Verifying CUDA Toolkit...
+echo ----------------------------------------
+nvcc --version >nul 2>&1
+if errorlevel 1 (
+    echo ERROR: nvcc not found. Please install CUDA Toolkit 12.6+
+    echo Download from: https://developer.nvidia.com/cuda-downloads
+    exit /b 1
+)
+nvcc --version
+echo.
+
+:: Step 3: Verify CMake
+echo [3/10] Verifying CMake...
+echo ----------------------------------------
+cmake --version >nul 2>&1
+if errorlevel 1 (
+    echo ERROR: cmake not found. Please install CMake.
+    echo Download from: https://cmake.org/download/
+    echo Or run: conda install -c conda-forge cmake
+    exit /b 1
+)
+cmake --version
+echo.
+
+:: Step 4: Install OptiX SDK headers
+echo [4/10] Setting up OptiX SDK headers...
+echo ----------------------------------------
+if exist "%OPTIX_DIR%\include\optix.h" (
+    echo OptiX headers already installed at %OPTIX_DIR%
+) else (
+    echo Cloning OptiX SDK headers from NVIDIA/optix-dev...
+    if exist "%OPTIX_DIR%" rmdir /s /q "%OPTIX_DIR%"
+    git clone --depth 1 --branch %OPTIX_VERSION% https://github.com/NVIDIA/optix-dev.git "%OPTIX_DIR%"
+    if errorlevel 1 (
+        echo ERROR: Failed to clone OptiX headers
+        exit /b 1
+    )
+    if not exist "%OPTIX_DIR%\include\optix.h" (
+        echo ERROR: OptiX headers not found after clone
+        exit /b 1
+    )
+    echo OptiX headers installed successfully
+)
+set OptiX_INSTALL_DIR=%OPTIX_DIR%
+echo.
+
+:: Step 5: Set up Visual Studio environment for nvcc
+echo [5/10] Setting up Visual Studio environment...
+echo ----------------------------------------
+:: Check if cl.exe is already available
+where cl.exe >nul 2>&1
+if not errorlevel 1 (
+    echo Visual Studio environment already configured
+    goto :vs_done
+)
+
+:: Use vswhere to find Visual Studio installation (most reliable method)
+set "VSWHERE=%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe"
+set "VCVARS_PATH="
+
+if exist "%VSWHERE%" (
+    echo Using vswhere to locate Visual Studio...
+    for /f "usebackq tokens=*" %%i in (`"%VSWHERE%" -latest -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath`) do (
+        set "VS_PATH=%%i"
+    )
+    if defined VS_PATH (
+        set "VCVARS_PATH=!VS_PATH!\VC\Auxiliary\Build\vcvars64.bat"
+    )
+)
+
+:: Fallback: try common paths if vswhere didn't work
+if not defined VCVARS_PATH (
+    echo vswhere not found or no VS with C++ tools, trying common paths...
+    for %%p in (
+        "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+        "C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\VC\Auxiliary\Build\vcvars64.bat"
+    ) do (
+        if not defined VCVARS_PATH (
+            if exist %%p (
+                set "VCVARS_PATH=%%~p"
+            )
+        )
+    )
+)
+
+if not defined VCVARS_PATH (
+    echo ERROR: Could not find Visual Studio with C++ tools.
+    echo.
+    echo Please install Visual Studio with C++ build tools:
+    echo   winget install Microsoft.VisualStudio.2022.Community --silent --override "--wait --quiet --add Microsoft.VisualStudio.Workload.NativeDesktop --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 --includeRecommended"
+    echo.
+    echo Or run this script from "x64 Native Tools Command Prompt for VS 2022"
+    exit /b 1
+)
+
+echo Found: %VCVARS_PATH%
+echo Initializing Visual Studio environment...
+call "%VCVARS_PATH%"
+if errorlevel 1 (
+    echo ERROR: Failed to initialize Visual Studio environment
+    exit /b 1
+)
+
+:: Verify cl.exe is now available
+where cl.exe >nul 2>&1
+if errorlevel 1 (
+    echo.
+    echo ERROR: cl.exe still not found after running vcvars64.bat
+    echo The C++ compiler may not be installed. Please ensure you have installed
+    echo the "Desktop development with C++" workload in Visual Studio.
+    echo.
+    echo You can add it by running:
+    echo   "%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vs_installer.exe" modify --installPath "!VS_PATH!" --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64
+    echo.
+    echo Or run this script from "x64 Native Tools Command Prompt for VS 2022"
+    exit /b 1
+)
+echo.
+echo Visual Studio environment configured successfully
+echo Compiler:
+where cl.exe
+:vs_done
+echo.
+
+:: Step 6: Detect GPU architecture
+echo [6/10] Detecting GPU architecture...
+echo ----------------------------------------
+:: Use skip=1 to skip the CSV header line since noheader may not be supported
+for /f "skip=1 tokens=*" %%i in ('nvidia-smi --query-gpu=compute_cap --format=csv') do (
+    if not defined COMPUTE_CAP set "COMPUTE_CAP=%%i"
+)
+:: Remove the dot from compute capability (e.g., 8.6 -> 86)
+set GPU_ARCH=%COMPUTE_CAP:.=%
+echo Detected GPU compute capability: sm_%GPU_ARCH%
+echo.
+
+:: Step 7: Compile PTX
+echo [7/10] Compiling kernel.cu to PTX...
+echo ----------------------------------------
+if not exist "cuda\kernel.cu" (
+    echo ERROR: cuda\kernel.cu not found. Are you in the rtxpy directory?
+    exit /b 1
+)
+nvcc -ptx -arch=sm_%GPU_ARCH% -I"%OptiX_INSTALL_DIR%\include" -Icuda --use_fast_math -o rtxpy\kernel.ptx cuda\kernel.cu
+if errorlevel 1 (
+    echo ERROR: PTX compilation failed
+    exit /b 1
+)
+echo PTX compiled successfully to rtxpy\kernel.ptx
+echo.
+
+:: Step 8: Install otk-pyoptix
+echo [8/10] Installing otk-pyoptix...
+echo ----------------------------------------
+
+:: Verify OptiX_INSTALL_DIR is set and valid
+if not defined OptiX_INSTALL_DIR (
+    set "OptiX_INSTALL_DIR=%OPTIX_DIR%"
+)
+if not exist "%OptiX_INSTALL_DIR%\include\optix.h" (
+    echo ERROR: OptiX headers not found at %OptiX_INSTALL_DIR%\include
+    echo Please ensure step 4 completed successfully.
+    exit /b 1
+)
+echo Using OptiX_INSTALL_DIR=%OptiX_INSTALL_DIR%
+
+python -c "import optix" >nul 2>&1
+if errorlevel 1 (
+    echo otk-pyoptix not found, installing from source...
+    if exist "%TEMP%\otk-pyoptix" rmdir /s /q "%TEMP%\otk-pyoptix"
+    git clone --depth 1 https://github.com/NVIDIA/otk-pyoptix.git "%TEMP%\otk-pyoptix"
+    if errorlevel 1 (
+        echo ERROR: Failed to clone otk-pyoptix
+        exit /b 1
+    )
+
+    :: Pre-clone pybind11 without submodules to avoid FetchContent submodule update failures
+    echo Pre-cloning pybind11 to avoid submodule issues...
+    set "PYBIND11_DIR=%TEMP%\pybind11-src"
+    if exist "!PYBIND11_DIR!" rmdir /s /q "!PYBIND11_DIR!"
+    git clone --depth 1 --branch v2.13.6 https://github.com/pybind/pybind11.git "!PYBIND11_DIR!"
+    if errorlevel 1 (
+        echo ERROR: Failed to clone pybind11
+        exit /b 1
+    )
+
+    :: Tell CMake to use our pre-cloned pybind11 instead of fetching
+    set "FETCHCONTENT_SOURCE_DIR_PYBIND11=!PYBIND11_DIR!"
+    echo Using pre-cloned pybind11 at !PYBIND11_DIR!
+
+    pushd "%TEMP%\otk-pyoptix\optix"
+
+    :: Patch CMakeLists.txt to use our pre-cloned pybind11 and skip submodule updates
+    echo Patching CMakeLists.txt to use local pybind11...
+
+    :: Convert backslashes to forward slashes for CMake
+    set "PYBIND11_DIR_CMAKE=!PYBIND11_DIR:\=/!"
+
+    :: Prepend the FETCHCONTENT_SOURCE_DIR_PYBIND11 setting to CMakeLists.txt
+    :: Use parentheses with echo to create file with newline, then use type to append
+    (
+        echo set^(FETCHCONTENT_SOURCE_DIR_PYBIND11 "!PYBIND11_DIR_CMAKE!" CACHE PATH "pybind11 source" FORCE^)
+        type CMakeLists.txt
+    ) > "%TEMP%\CMakeLists_new.txt"
+    move /y "%TEMP%\CMakeLists_new.txt" CMakeLists.txt >nul
+
+    echo Patched CMakeLists.txt - first 2 lines:
+    powershell -Command "Get-Content CMakeLists.txt -Head 2"
+
+    :: Set OptiX path for cmake/pip build process
+    set "OptiX_INSTALL_DIR=%OptiX_INSTALL_DIR%"
+    set "OPTIX_PATH=%OptiX_INSTALL_DIR%"
+    set "CMAKE_PREFIX_PATH=%OptiX_INSTALL_DIR%;%CMAKE_PREFIX_PATH%"
+
+    :: Pre-install build dependencies so we can use --no-build-isolation
+    echo Installing build dependencies...
+    pip install setuptools wheel
+
+    echo Building with OptiX_INSTALL_DIR=%OptiX_INSTALL_DIR%
+    echo FETCHCONTENT_SOURCE_DIR_PYBIND11=!FETCHCONTENT_SOURCE_DIR_PYBIND11!
+
+    :: Pass pybind11 source dir to CMake via CMAKE_ARGS (used by scikit-build and setuptools)
+    set "CMAKE_ARGS=-DFETCHCONTENT_SOURCE_DIR_PYBIND11=!PYBIND11_DIR!"
+
+    :: Use --no-build-isolation so environment variables are visible to CMake
+    pip install . -v --no-build-isolation
+    if errorlevel 1 (
+        echo.
+        echo ERROR: Failed to install otk-pyoptix
+        echo.
+        echo If the error mentions OptiX not found, try setting manually:
+        echo   set OptiX_INSTALL_DIR=%OptiX_INSTALL_DIR%
+        echo   set OPTIX_PATH=%OptiX_INSTALL_DIR%
+        echo.
+        popd
+        exit /b 1
+    )
+    popd
+    echo otk-pyoptix installed successfully
+) else (
+    echo otk-pyoptix already installed
+)
+echo.
+
+:: Step 9: Install rtxpy
+echo [9/10] Installing rtxpy with test dependencies...
+echo ----------------------------------------
+pip install -U pip
+pip install -ve .[tests,cuda12]
+if errorlevel 1 (
+    echo ERROR: Failed to install rtxpy
+    exit /b 1
+)
+echo.
+
+:: Step 10: Run tests
+echo [10/10] Running GPU tests...
+echo ----------------------------------------
+echo.
+echo === Running pytest ===
+python -m pytest -v rtxpy/tests
+set PYTEST_RESULT=%errorlevel%
+echo.
+
+echo === Running basic ray tracing test ===
+python -c "from rtxpy import RTX; import numpy as np; verts = np.float32([0,0,0, 1,0,0, 0,1,0, 1,1,0]); triangles = np.int32([0,1,2, 2,1,3]); rays = np.float32([0.33,0.33,100, 0,0,0, -1,1000]); hits = np.float32([0,0,0,0]); optix = RTX(); res = optix.build(0, verts, triangles); assert res == 0, f'Build failed with {res}'; res = optix.trace(rays, hits, 1); assert res == 0, f'Trace failed with {res}'; print(f'Hit result: t={hits[0]}, normal=({hits[1]}, {hits[2]}, {hits[3]})'); assert hits[0] > 0, 'Expected a hit'; print('GPU ray tracing test PASSED!')"
+set RAYTEST_RESULT=%errorlevel%
+echo.
+
+:: Summary
+echo ============================================
+echo Test Summary
+echo ============================================
+if %PYTEST_RESULT% equ 0 (
+    echo pytest:           PASSED
+) else (
+    echo pytest:           FAILED
+)
+if %RAYTEST_RESULT% equ 0 (
+    echo ray tracing test: PASSED
+) else (
+    echo ray tracing test: FAILED
+)
+echo ============================================
+
+if %PYTEST_RESULT% neq 0 exit /b %PYTEST_RESULT%
+if %RAYTEST_RESULT% neq 0 exit /b %RAYTEST_RESULT%
+
+echo.
+echo All GPU tests completed successfully!
+exit /b 0