How can you capture the visual texture of fabric for high-end, online retail? Well this is the exact challenge that fashion retail start-up Change of Paradigm and University College London (UCL) gave robotics consultancy Robotae, as part of a twelve month Innovate UK-funded project.
London and Paris based Change of Paradigm is developing a B2C e-commerce platform, offering exclusive capsule collections from independent women’s wear designers. The aim is to provide luxury fashion to ‘digital native’ millennial women at an affordable price, by selling exclusively from photorealistic 3D simulated garments before they’re produced, eliminating over-production.
In this early stage of the programme, Robotae has designed a gonioreflectometer to take images of textile samples from different angles, illuminated from many directions to measure their reflectance. By gathering these visual properties, the eventual 3D rendered images will display accurate texture and movement of the materials.
Robotae’s Director, Dr Kevin Rathbone, designed and built the device at Robotae’s offices in St John’s Innovation Centre, Cambridge, including construction of a purpose-built darkroom to house the system.
Rathebone explained: “The device moves a digital camera to any position around the textile sample; a high quality spotlight is independently moved around the sample, providing uniform illumination from any direction. Smooth motion is essential to eliminate any vibration at the end of the movements, which would introduce blur into the images.
“The machine follows a simple scripting language to automatically capture a large number of images at up to one image every 1.6s. The longest run to date is 10,000 images, with scripts of up to 26,000 images planned later in the research programme. The images are captured over USB using the Canon EDSDK API and streamed onto a solid state hard drive, which is then sent to a team at University College London (UCL). Using a high-performance computing cluster they are able to extract the particular properties of the materials that are needed for state-of-the-art rendering.”
Tim Weyrich, Professor of Visual Computing at UCL, is a specialist in the measurement and acquisition of surface reflectance of complex materials and is overseeing the project as technical authority.
“Most gonioreflectometer designs would put the textile sample on a turntable, so you could avoid rotating your camera around it,” said Weyrich. “We had to do this in a more sophisticated way, as when you are photographing a delicate structure, it can change the moment you move it. So it was very important that the sample we imaged was motionless and static.”
When it came to implementing this design, he found it difficult to find a development partner who met all the requirements.
Weyrich explained: “We were looking for a unicorn. It was quite difficult to find someone with a good understanding of the scientific approach, mechanical engineering, electrical engineering, computer science and with the capability of communicating on an abstract and detailed level for the final specification.
“Most potential contractors specialised in either robotics or cameras alone, but Dr Kevin Rathbone at Robotae knew how to do both.”
He continued: “The gonioreflectometer is a flexible proof of concept, standing with one foot in the domain of academic research, where there are a lot of unknowns. We chose Kevin due to his comprehensive experience, scientific background and understanding of working with academia.”
Change of Paradigm is currently obtaining further funding for the next stages of development.