# Footprint to 3D Solid Extruder

> Turn a simple footprint into a closed 3D solid with OBJ, STL and editable geometry. Enter a polygon footprint and extrusion height to make a closed 3D prism. Set its placement and rotation, measure surface and volume, and open the editable result in Kerfwise Form Studio.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://kerfwiseprofileextruder.usefulweb.site/ (interactive tool at https://kerfwiseprofileextruder.usefulweb.site/tool)
- JSON API: POST https://kerfwiseprofileextruder.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://kerfwiseprofileextruder.usefulweb.site/api/v1/tool)
- OpenAPI: https://kerfwiseprofileextruder.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://kerfwiseprofileextruder.usefulweb.site/mcp - tool `kerfwise_profile_extruder`

## Inputs
- points (textarea): Footprint X,Y pairs in mm (one per line)
- height (number): Extrusion height (mm)
- x (number): Origin X (mm)
- y (number): Origin Y (mm)
- z (number): Base elevation (mm)
- rotation (number): Rotation around Z (degrees)
- name (text): Solid name
- color (text): Solid color (HEX)

## Method
- All geometry is in millimetres, with Z up. Accept one simple, non-self-intersecting footprint without holes, 3–64 vertices and at least 1 mm² area. Extrude vertically, then rotate around Z and translate.
- Triangulate both caps and each side with consistent outward winding. Each separate prism is closed; intersecting prisms are not unioned. Surface = 2 × footprint area + perimeter × height; gross volume = footprint area × height.
- Models contain at most 128 solids and eight saved camera views. Coordinates, heights and profiles are bounded. OBJ and ASCII STL use millimetres; STL does not embed a unit. These are concept models, separate from cabinet cut lists or machining instructions.

## Limits
- Concept geometry only. Separate shells are not fused; gross quantities include overlaps. Not cabinet manufacturing output.