# skip_depth=true vs skip_depth=false in MCP 3D Relief: Depth Map Modes Explained

> Understand skip_depth=true vs skip_depth=false in MCP 3D Relief. Learn how each depth map mode processes images for sophisticated depth extraction or simplified grayscale conversion.

- Repository: [bigchx/mcp_3d_relief](https://github.com/bigchx/mcp_3d_relief)
- Tags: deep-dive
- Published: 2026-02-26

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**Setting `skip_depth=True` triggers the `generate_depth_map` coroutine for sophisticated depth extraction, while `skip_depth=False` (default) uses a simplified grayscale-to-depth conversion that processes the image directly without dedicated depth analysis.**

The `skip_depth` boolean flag in the `bigchx/mcp_3d_relief` repository controls how input images are converted into height maps for 3D relief generation. Located within the main `relief` function in [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py), this parameter determines whether the system leverages a computationally intensive depth pipeline or a fast preprocessing shortcut. Understanding the difference between `skip_depth=true` and `skip_depth=false` modes is essential for balancing processing speed against the geometric fidelity of your final STL output.

## How skip_depth Controls Depth Map Generation

In [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py) (lines 1675–1735), the `skip_depth` parameter acts as a conditional switch between two distinct image processing strategies. Despite its potentially misleading name, this flag does not control whether depth information is output—both modes produce a depth-map image and an STL file—but rather determines the algorithmic complexity of how luminance values translate to height data.

## skip_depth=false: The Fast Grayscale Fallback

When `skip_depth` is set to `False` (the default), the system bypasses the dedicated depth analysis routine in favor of computational efficiency. According to the source code at lines 1717–1730, this path processes the input through a lightweight pipeline:

- Converts the image to grayscale
- Rescales to the target detail level
- Applies a small Gaussian blur
- Optionally inverts the values
- **Uses this processed image directly as the depth map**

The code comments explicitly mark this as "Using original image directly (skipping depth conversion)...", confirming that `False` effectively skips the sophisticated depth-generation step.

```python

# Fast mode: Simple grayscale conversion (skip_depth=False)

await relief(
    input_image_path="example.jpg",
    detail_level=1.0,
    skip_depth=False,  # Default; uses resized, blurred grayscale image

)

```

## skip_depth=true: Full Depth Map Generation

Setting `skip_depth=True` enables the complete depth-map pipeline by invoking the `generate_depth_map` coroutine. When this flag is enabled, the logic at lines 1731–1735 in [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py) triggers a more sophisticated analysis implemented at lines 25–49 of the same file.

The `generate_depth_map` routine performs:

- Image resizing to target dimensions
- **Power-law luminance transformation** for enhanced depth perception
- Optional inversion handling
- **Stronger Gaussian blur** for smooth height transitions

This approach mimics actual depth extraction rather than relying on raw luminance values.

```python

# Quality mode: Full depth generation (skip_depth=True)

await relief(
    input_image_path="example.jpg",
    detail_level=1.0,
    skip_depth=True,  # Triggers generate_depth_map for richer depth data

)

```

## Performance and Quality Implications

The distinction between these modes affects both output characteristics and resource utilization:

- **`skip_depth=False`**: Optimal for rapid prototyping or when processing images with inherently high contrast. This path minimizes CPU overhead but may produce flatter relief structures in complex scenes.
- **`skip_depth=True`**: Better suited for detailed 3D prints requiring nuanced height variations. The power-law transformation better approximates how human perception interprets shading as depth, though it requires additional processing time.

Both modes write their results to the `output` directory, generating both a depth-map image and a corresponding STL file.

## Summary

- **`skip_depth=False`** (default): Employs a fast grayscale conversion with basic Gaussian blur at lines 1717–1730—ideal for speed and simple contrast-to-height mappings.
- **`skip_depth=True`**: Invokes `generate_depth_map` (lines 25–49) with power-law luminance transforms and enhanced smoothing for superior depth interpretation.
- **Counterintuitive naming**: The flag behaves opposite to literal reading; `True` enables depth generation, while `False` skips the dedicated depth pipeline.
- **Source locations**: Conditional logic resides in [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py) lines 1675–1735, with the depth generation algorithm defined at lines 25–49.

## Frequently Asked Questions

### What is the default value of skip_depth in mcp_3d_relief?

The default value is `False`, meaning the system uses the fast grayscale conversion method unless explicitly configured otherwise. This ensures faster processing times for standard use cases.

### Why does skip_depth=true enable depth generation instead of skipping it?

The flag name is counterintuitive relative to the implementation. When set to `True`, the code **enables** the `generate_depth_map` coroutine (lines 1731–1735), while `False` **skips** that routine and falls back to simple image preprocessing (lines 1717–1730). The naming reflects the internal logic of skipping the "fast path" rather than skipping depth generation itself.

### Which mode should I use for high-quality 3D prints?

Use `skip_depth=True` for high-quality results requiring nuanced topography. The `generate_depth_map` function applies power-law luminance transformations (lines 25–49) that better interpret visual shading as physical depth compared to the basic grayscale conversion used when the flag is `False`.

### Where is the depth map generation logic implemented in the source code?

The conditional switching logic is implemented in [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py) at lines 1717–1735, which determines whether to use the fast grayscale path or invoke the coroutine. The actual depth generation algorithm resides in the `generate_depth_map` coroutine at lines 25–49 of [`relief.py`](https://github.com/bigchx/mcp_3d_relief/blob/main/relief.py).