diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..209c67e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,159 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# pipenv
+Pipfile.lock
+
+# poetry
+poetry.lock
+
+# pdm
+.pdm.toml
+.pdm-python
+.pdm-build/
+
+# PEP 582
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# IDE settings
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# Claude settings
+.claude/*
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Project specific
+output/
+checkpoints/
+data/
+wandb/
+runs/
\ No newline at end of file
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..35613b6
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,23 @@
+# CLAUDE.md - Project Context
+
+This file contains important context and instructions for Claude Code.
+
+## Project Overview
+Python project requiring testing infrastructure setup.
+
+## Commands to Run After Code Changes
+- `poetry run test` - Run all tests
+- `poetry run lint` - Run linting (if configured)
+- `poetry run typecheck` - Run type checking (if configured)
+
+## Testing Infrastructure
+- Package manager: Poetry (or UV if detected)
+- Test framework: pytest
+- Coverage: pytest-cov
+- Test directories: tests/unit/, tests/integration/
+
+## Important Notes
+- Always run tests after making changes
+- Coverage threshold is currently set to 0% for infrastructure setup
+- **TODO**: Change `--cov-fail-under=0` to `--cov-fail-under=80` in pyproject.toml after writing tests
+- Use conventional commit messages
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..0f477a9
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,85 @@
+[tool.poetry]
+name = "gaussian-splatting"
+version = "0.1.0"
+description = "3D Gaussian Splatting for Real-Time Radiance Field Rendering"
+authors = ["Your Name <you@example.com>"]
+readme = "README.md"
+packages = [{include = "scene"}, {include = "utils"}, {include = "arguments"}, {include = "gaussian_renderer"}, {include = "lpipsPyTorch"}, {include = "scripts"}]
+
+[tool.poetry.dependencies]
+python = "^3.8"
+plyfile = "*"
+opencv-python = "*"
+lpips = "*"
+trimesh = "*"
+numpy = "*"
+torch = "*"
+
+[tool.poetry.group.dev.dependencies]
+pytest = "^7.4.0"
+pytest-cov = "^4.1.0"
+pytest-mock = "^3.11.1"
+
+[tool.poetry.scripts]
+test = "pytest:main"
+tests = "pytest:main"
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py", "*_test.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = [
+    "-v",
+    "--strict-markers",
+    "--tb=short",
+    "--cov=scene",
+    "--cov=utils",
+    "--cov=arguments", 
+    "--cov=gaussian_renderer",
+    "--cov=lpipsPyTorch",
+    "--cov-report=html",
+    "--cov-report=xml",
+    "--cov-report=term-missing",
+    "--cov-fail-under=0"
+]
+markers = [
+    "unit: Unit tests",
+    "integration: Integration tests",
+    "slow: Slow running tests"
+]
+
+[tool.coverage.run]
+source = ["scene", "utils", "arguments", "gaussian_renderer", "lpipsPyTorch"]
+omit = [
+    "*/tests/*",
+    "*/test_*.py",
+    "*/__pycache__/*",
+    "*/site-packages/*",
+    "setup.py",
+    "*/migrations/*"
+]
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "def __repr__",
+    "if self.debug:",
+    "if settings.DEBUG",
+    "raise AssertionError",
+    "raise NotImplementedError",
+    "if 0:",
+    "if __name__ == .__main__.:"
+]
+show_missing = true
+precision = 2
+
+[tool.coverage.html]
+directory = "htmlcov"
+
+[tool.coverage.xml]
+output = "coverage.xml"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"
\ No newline at end of file
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..687b583
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,175 @@
+"""Shared pytest fixtures and configuration for all tests."""
+
+import os
+import tempfile
+import shutil
+from pathlib import Path
+from typing import Generator, Dict, Any
+import pytest
+import numpy as np
+
+
+@pytest.fixture
+def temp_dir() -> Generator[Path, None, None]:
+    """Create a temporary directory for test files."""
+    temp_path = tempfile.mkdtemp()
+    yield Path(temp_path)
+    shutil.rmtree(temp_path)
+
+
+@pytest.fixture
+def mock_config() -> Dict[str, Any]:
+    """Provide a mock configuration dictionary for testing."""
+    return {
+        "model_path": "/tmp/test_model",
+        "source_path": "/tmp/test_data",
+        "iterations": 100,
+        "test_iterations": [50, 100],
+        "save_iterations": [50, 100],
+        "checkpoint_iterations": [],
+        "resolution": 1,
+        "white_background": False,
+        "data_device": "cpu",
+        "eval": False,
+        "sh_degree": 3,
+        "feature_lr": 0.0025,
+        "opacity_lr": 0.05,
+        "scaling_lr": 0.005,
+        "rotation_lr": 0.001,
+        "position_lr_init": 0.00016,
+        "position_lr_final": 0.0000016,
+        "position_lr_delay_mult": 0.01,
+        "position_lr_max_steps": 30000,
+        "percent_dense": 0.01,
+        "lambda_dssim": 0.2,
+        "densification_interval": 100,
+        "opacity_reset_interval": 3000,
+        "densify_from_iter": 500,
+        "densify_until_iter": 15000,
+        "densify_grad_threshold": 0.0002,
+    }
+
+
+@pytest.fixture
+def sample_point_cloud() -> np.ndarray:
+    """Generate a sample 3D point cloud for testing."""
+    num_points = 100
+    points = np.random.randn(num_points, 3).astype(np.float32)
+    return points
+
+
+@pytest.fixture
+def sample_image_data() -> np.ndarray:
+    """Generate sample image data for testing."""
+    height, width = 64, 64
+    image = np.random.rand(height, width, 3).astype(np.float32)
+    return image
+
+
+@pytest.fixture
+def mock_camera_params() -> Dict[str, Any]:
+    """Provide mock camera parameters for testing."""
+    return {
+        "width": 800,
+        "height": 600,
+        "fovx": 1.0472,  # 60 degrees in radians
+        "fovy": 0.7854,  # 45 degrees in radians
+        "znear": 0.01,
+        "zfar": 100.0,
+        "world_view_transform": np.eye(4, dtype=np.float32),
+        "full_proj_transform": np.eye(4, dtype=np.float32),
+        "camera_center": np.array([0, 0, 0], dtype=np.float32),
+    }
+
+
+@pytest.fixture
+def temp_ply_file(temp_dir: Path, sample_point_cloud: np.ndarray) -> Path:
+    """Create a temporary PLY file with sample point cloud data."""
+    ply_path = temp_dir / "test_points.ply"
+    
+    # Simple PLY file writing (minimal implementation for testing)
+    with open(ply_path, 'w') as f:
+        f.write("ply\n")
+        f.write("format ascii 1.0\n")
+        f.write(f"element vertex {len(sample_point_cloud)}\n")
+        f.write("property float x\n")
+        f.write("property float y\n")
+        f.write("property float z\n")
+        f.write("end_header\n")
+        
+        for point in sample_point_cloud:
+            f.write(f"{point[0]} {point[1]} {point[2]}\n")
+    
+    return ply_path
+
+
+@pytest.fixture
+def mock_training_args():
+    """Mock training arguments for testing."""
+    class Args:
+        def __init__(self):
+            self.source_path = "/tmp/test_data"
+            self.model_path = "/tmp/test_model"
+            self.iterations = 1000
+            self.test_iterations = [500, 1000]
+            self.save_iterations = [1000]
+            self.checkpoint_iterations = []
+            self.quiet = True
+            self.resolution = 1
+            self.white_background = False
+            self.data_device = "cpu"
+            self.eval = False
+    
+    return Args()
+
+
+@pytest.fixture
+def capture_stdout(monkeypatch):
+    """Capture stdout for testing print statements."""
+    import io
+    import sys
+    
+    captured_output = io.StringIO()
+    
+    def _capture():
+        monkeypatch.setattr(sys, 'stdout', captured_output)
+        return captured_output
+    
+    return _capture
+
+
+@pytest.fixture(autouse=True)
+def reset_random_seed():
+    """Reset random seeds for reproducible tests."""
+    np.random.seed(42)
+    
+    # If using PyTorch
+    try:
+        import torch
+        torch.manual_seed(42)
+        if torch.cuda.is_available():
+            torch.cuda.manual_seed_all(42)
+    except ImportError:
+        pass
+
+
+@pytest.fixture
+def mock_gaussian_model_data() -> Dict[str, np.ndarray]:
+    """Provide mock data for Gaussian model testing."""
+    num_gaussians = 50
+    return {
+        "means": np.random.randn(num_gaussians, 3).astype(np.float32),
+        "scales": np.random.rand(num_gaussians, 3).astype(np.float32) * 0.1,
+        "rotations": np.random.randn(num_gaussians, 4).astype(np.float32),
+        "opacities": np.random.rand(num_gaussians, 1).astype(np.float32),
+        "features": np.random.rand(num_gaussians, 48).astype(np.float32),
+    }
+
+
+@pytest.fixture
+def environment_setup(monkeypatch):
+    """Set up test environment variables."""
+    monkeypatch.setenv("CUDA_VISIBLE_DEVICES", "")
+    monkeypatch.setenv("TEST_MODE", "1")
+    yield
+    # Cleanup happens automatically with monkeypatch
\ No newline at end of file
diff --git a/tests/integration/__init__.py b/tests/integration/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_setup_validation.py b/tests/test_setup_validation.py
new file mode 100644
index 0000000..d5eaef2
--- /dev/null
+++ b/tests/test_setup_validation.py
@@ -0,0 +1,104 @@
+"""Validation tests to ensure the testing infrastructure is properly set up."""
+
+import pytest
+from pathlib import Path
+import numpy as np
+
+
+def test_pytest_is_working():
+    """Basic test to verify pytest is working."""
+    assert True
+
+
+def test_fixtures_are_available(temp_dir, mock_config):
+    """Test that our fixtures are properly configured."""
+    assert isinstance(temp_dir, Path)
+    assert temp_dir.exists()
+    
+    assert isinstance(mock_config, dict)
+    assert "model_path" in mock_config
+    assert mock_config["iterations"] == 100
+
+
+def test_numpy_is_available():
+    """Test that numpy is available for tests."""
+    arr = np.array([1, 2, 3])
+    assert len(arr) == 3
+    assert arr.sum() == 6
+
+
+@pytest.mark.unit
+def test_unit_marker():
+    """Test that unit test marker works."""
+    assert 1 + 1 == 2
+
+
+@pytest.mark.integration
+def test_integration_marker():
+    """Test that integration test marker works."""
+    assert "integration" in "integration test"
+
+
+@pytest.mark.slow
+def test_slow_marker():
+    """Test that slow test marker works."""
+    # This would be a slow test in real scenarios
+    assert True
+
+
+def test_temp_dir_cleanup(temp_dir):
+    """Test that temporary directory is created and will be cleaned up."""
+    test_file = temp_dir / "test.txt"
+    test_file.write_text("test content")
+    
+    assert test_file.exists()
+    assert test_file.read_text() == "test content"
+
+
+def test_mock_camera_params(mock_camera_params):
+    """Test that camera parameters fixture provides expected data."""
+    assert mock_camera_params["width"] == 800
+    assert mock_camera_params["height"] == 600
+    assert "fovx" in mock_camera_params
+    assert isinstance(mock_camera_params["world_view_transform"], np.ndarray)
+
+
+def test_sample_point_cloud(sample_point_cloud):
+    """Test that sample point cloud fixture generates valid data."""
+    assert isinstance(sample_point_cloud, np.ndarray)
+    assert sample_point_cloud.shape == (100, 3)
+    assert sample_point_cloud.dtype == np.float32
+
+
+def test_temp_ply_file(temp_ply_file):
+    """Test that temporary PLY file is created correctly."""
+    assert temp_ply_file.exists()
+    assert temp_ply_file.suffix == ".ply"
+    
+    content = temp_ply_file.read_text()
+    assert "ply" in content
+    assert "element vertex" in content
+
+
+def test_coverage_is_tracked():
+    """Test to ensure coverage tracking is working."""
+    def sample_function(x, y):
+        if x > y:
+            return x
+        else:
+            return y
+    
+    assert sample_function(5, 3) == 5
+    assert sample_function(2, 7) == 7
+
+
+class TestClassBasedTests:
+    """Test that class-based tests work correctly."""
+    
+    def test_class_method(self):
+        """Test method in a test class."""
+        assert isinstance(self, TestClassBasedTests)
+    
+    def test_another_method(self, mock_config):
+        """Test that fixtures work in test classes."""
+        assert mock_config["sh_degree"] == 3
\ No newline at end of file
diff --git a/tests/unit/__init__.py b/tests/unit/__init__.py
new file mode 100644
index 0000000..e69de29