The figure in the 3D body visualizer is a mesh of about 13,500 points taken from the MakeHuman project.
A 3D body model is a mesh: a set of points in space joined into small flat faces that together form the surface of a body. Software changes the body by moving the points. The figure on this site is a mesh of about 13,500 points.
The 4 steps from numbers to a figure
The 3D body visualizer builds a figure in 4 steps: it starts from a base mesh, blends shape targets into the mesh, measures the result like a tape, and draws the surface in the browser.
| Step | What happens | On this site |
|---|---|---|
| Base mesh | A neutral adult body is loaded | The MakeHuman mesh, about 13,500 points |
| Shape targets | Stored changes, such as heavier or more muscular, are blended in | Weight, build and body shape settings |
| Measuring | The mesh is cut with a flat plane and the path around the cut is measured | 13 tape measurements |
| Drawing | The surface is lit and drawn | WebGL in the browser |
The base mesh and its shape targets
The base mesh comes from MakeHuman, an open source program for making 3D people. A shape target stores how far each point moves for one change of the body. Blending a target in by half moves each point half as far.
The tool searches for the blend of targets that gives the height, the weight and every tape measurement typed in. Weight is matched through volume: the tool works out the volume of the mesh in liters and multiplies it by a body density.
Measuring a mesh like a tape
A tape measurement on a mesh works the way a tape works on a person. The tool cuts the mesh with a flat plane at the level of the measurement and measures the tight path around the cut. Trunk measurements leave the arms out. The figure with its tape lines on shows 3 of those cuts as yellow lines.
Drawing the model in a browser
The figure is drawn with WebGL. The Khronos Group, which maintains the standard, describes WebGL as plugin-free 3D for the web. The whole model runs on the visitor's device, so the numbers typed in are not sent to a server.
Open source body models
MakeHuman publishes its work in the open. Its repository on GitHub holds the application, which is written in Python 3. The project's license page puts the source code under the AGPL and the core assets under CC0, which allows any use.
SMPL, a body model from the Max Planck Institute for Intelligent Systems, takes another route. SMPL is learned from thousands of 3D body scans. Its license allows non-commercial scientific research, education and artistic projects, and prohibits commercial use under that license.
The 3D body visualizer uses the MakeHuman mesh and code written for this site. The history of the scan-based models is in the guide on where the body visualizer came from.