# 54. Organic Modeling Tools (TASK-038)

**Date:** 2025-11-30
**Version:** 1.27.0
**Task:** [TASK-038](../_TASKS/TASK-038_Organic_Modeling_Tools.md)

---

## Summary

Implemented comprehensive organic modeling tools for medical/biological visualization, creature design, and VFX workflows. These tools enable creation of organic structures like organs, blood vessels, tumors, and cellular structures.

---

## New Tools

### Metaball Tools (TASK-038-1)

| Tool | Description |
|------|-------------|
| `metaball_create` | Creates metaball object with configurable element type (BALL, CAPSULE, ELLIPSOID, etc.) |
| `metaball_add_element` | Adds elements to existing metaball for organic merging |
| `metaball_to_mesh` | Converts metaball to mesh for further editing |

### Core Sculpt Brushes (TASK-038-2)

| Tool | Description |
|------|-------------|
| `sculpt_brush_clay` | Clay brush for adding material (muscle mass, fat deposits) |
| `sculpt_brush_inflate` | Inflate brush for pushing geometry outward (swelling, tumors) |
| `sculpt_brush_blob` | Blob brush for creating rounded organic bulges |

### Detail Sculpt Brushes (TASK-038-3)

| Tool | Description |
|------|-------------|
| `sculpt_brush_snake_hook` | Snake hook for pulling tendrils (blood vessels, nerves) |
| `sculpt_brush_draw` | Basic draw brush for general sculpting |
| `sculpt_brush_pinch` | Pinch brush for creating sharp creases (wrinkles, folds) |

### Dynamic Topology (TASK-038-4)

| Tool | Description |
|------|-------------|
| `sculpt_enable_dyntopo` | Enables dynamic topology with RELATIVE/CONSTANT/BRUSH/MANUAL modes |
| `sculpt_disable_dyntopo` | Disables dynamic topology |
| `sculpt_dyntopo_flood_fill` | Applies current detail level to entire mesh |

### Proportional Editing (TASK-038-5)

| Tool | Description |
|------|-------------|
| `mesh_set_proportional_edit` | Configures proportional editing with falloff types (SMOOTH, SHARP, etc.) |

### Skin Modifier Workflow (TASK-038-6)

| Tool | Description |
|------|-------------|
| `skin_create_skeleton` | Creates skeleton mesh with auto Skin modifier for tubular structures |
| `skin_set_radius` | Sets skin radius at vertices for varying thickness |

---

## Files Modified

### Server (MCP)
- `server/domain/tools/sculpt.py` - Added 9 new abstract methods
- `server/domain/tools/modeling.py` - Added 5 metaball/skin methods
- `server/domain/tools/mesh.py` - Added proportional editing method
- `server/application/tool_handlers/sculpt_handler.py` - Implemented new methods
- `server/application/tool_handlers/modeling_handler.py` - Implemented new methods
- `server/application/tool_handlers/mesh_handler.py` - Implemented proportional edit
- `server/adapters/mcp/areas/sculpt.py` - Added MCP tool definitions
- `server/adapters/mcp/areas/modeling.py` - Added MCP tool definitions
- `server/adapters/mcp/areas/mesh.py` - Added proportional editing tool

### Blender Addon
- `blender_addon/application/handlers/sculpt.py` - Added 9 brush/dyntopo methods
- `blender_addon/application/handlers/modeling.py` - Added metaball/skin methods
- `blender_addon/application/handlers/mesh.py` - Added proportional editing
- `blender_addon/__init__.py` - Registered 16 new RPC handlers

### Tests
- `tests/unit/tools/sculpt/test_sculpt_tools.py` - Added 25 new tests
- `tests/unit/tools/modeling/test_modeling_tools.py` - Added 17 new tests
- `tests/unit/tools/mesh/test_mesh_organic.py` - New test file with 10 tests

---

## Example Workflows

### Heart Model
```python
# Start with metaball for main chambers
metaball_create(name="Heart", element_type="ELLIPSOID", radius=1.0)
metaball_add_element("Heart", element_type="BALL", location=[0.5, 0, 0.3], radius=0.8)
metaball_to_mesh("Heart")

# Enable dyntopo for detail sculpting
sculpt_enable_dyntopo(detail_mode="RELATIVE", detail_size=8)

# Shape with brushes
sculpt_brush_clay()
sculpt_brush_pinch()
```

### Blood Vessels
```python
# Create vessel skeleton with branching
skin_create_skeleton(
    name="Artery",
    vertices=[[0,0,0], [0,0,1], [0.3,0,1.5], [-0.3,0,1.5]],
    edges=[[0,1], [1,2], [1,3]]
)

# Adjust radii for varying thickness
skin_set_radius("Artery", vertex_index=0, radius_x=0.15)
skin_set_radius("Artery", vertex_index=[2,3], radius_x=0.08)
```

---

## Test Results

- **Unit Tests:** 662 passed (52 new tests for TASK-038)
- **E2E Tests:** Pending (requires addon update in Blender)

---

## Notes

- Metaballs automatically merge when close together, ideal for organic shapes
- Dynamic Topology (Dyntopo) destroys UV maps and vertex groups - use for concept/base mesh
- Skin modifier creates smooth tubular mesh from skeleton - perfect for blood vessels
- Proportional editing affects nearby geometry during transforms - essential for organic deformations
