Please use FileSystem tools to finish the following task:

### Task Description

ThreeStudio is a comprehensive codebase that implements various diffusion-based text-to-3D models, including NeRF-based rendering stage and diffusion guidance stage. Your task is to explore the codebase and identify the specific file that defines the guidance functionality for the Zero123 model.

### Task Objectives

1. **Explore the ThreeStudio codebase** using filesystem MCP tools
2. **Search through the project structure** to understand the codebase organization
3. **Identify the file** that contains the Zero123 guidance implementation
4. **Create an answer file** with the correct file path

### Expected Output

Create a file named `answer.txt` in the test directory root

**Requirements:**
- Only include the file path, no additional text or explanation
- Use forward slashes (/) for path separators
- Include the full relative path from the project root
- Ensure the path points to the actual file that defines Zero123 guidance