Mannequin

By Angel Chen

Description

Objective

The goal was to model the skirt from A8 onto a mannequin. I wanted to implement this so that if polished and heavily developed on, users can scan their body, generate a 3D model (currently using a mesh 3D model from Mixamo), and try on clothing to see how they would look and move with such clothing.

New Feature

The main feature I implemented was collision detection for the body and the skirt. The collision adjustment can be found in sphere_collision.cpp and it is added onto fast_mass_springs_step_sparse per each iteration at the end.

Process

Using the idea that we can simplify collision detection by using simple geometry shapes, I modelled a sphere with set radius and center to fit the mesh 3D model’s waist. I had to use Blender to scale and transform the skirt’s position so that it would fit on the model. Then, also in Blender, I took their sphere mesh and triangulated it, then exported it to use and test the skirt collision with first. After I was comfortable with how it looked on the sphere, I fitted it on the model and made minor adjustments.

I wrote two helper functions to create the main JSON file with the model and skirt details, including the vast amount of b values needed to pin the model. The second function was to merge the skirt and model .obj files. A8’s read_json.h function was only able to process one object at a time, and considering assignment priorities, I decided to merge the two object files.

Future Improvements

  1. I want to rewrite the read_json.h file to process multiple objects and their respective png textures. This way, it would be easier to distinguish between the model and the skirt.

  2. I also want to model the mannequin’s waist with two spheres next time to simulate the hips and waist better.

Acknowledgements

Sphere from Blender

Blender. (2025). UV Sphere Node - Blender 5.0 Manual. Blender.org. https://docs.blender.org/manual/en/latest/modeling/geometry_nodes/mesh/primitives/uv_sphere.htmlMixamo Inc. (n.d.).

Model [X-Bot] from Mixamo

Mixamo. <Www.mixamo.com>. https://www.mixamo.com/#/

JSON creating library

Software Foundation. (2023). json — JSON encoder and decoder — Python 3.8.3rc1 documentation. Docs.python.org. https://docs.python.org/3/library/json.html