Photogrammetry and capturing process

Photogrammetry is an engineering discipline that helps obtain information about a physical object. This is done through the processes of measuring and recording photographic images and afterwards analysing them. Photogrammetry has evolved in parallel with digital technologies. Nowadays, we are in the phase of the so-called digital photogrammetry. In this phase the use of computer software helps to make the process more automated with fewer human interaction. The digital images are placed in the processing software where a photogrammetric analysis and synthesis is performed (Papadopoulos, n.d.).

For this project we used one of the photogrammetry techniques, namely the Structure from Motion (SfM), in order to create the 3D model of Mickey Mouse. SfM combines computer vision and photogrammetry by analysing and reconstructing camera positions and geometry of the captured object. This technique helps to understand the 3D structure of an object and therefore enables to produce an accurate and high quality 3D model. There are many SfM softwares that are available, both free and with a subscription. For this course we used the Agisoft Metashape software (Papadopoulos, n.d.).

In the process of creating the 3D model of Mickey Mouse plush toy we followed a number of steps. First of all, we needed to take a number of images with the help of a digital camera. In this step, it was important to make sure that all camera settings are set right, such as ISO, aperture, white balance and manual focus to capture a still object with the same lighting on each image. As required by the SfM technique, we took a number of images in a hemisphere shape to ensure full coverage of the object. It was equally essential to bear in mind the 60% overlap of the images to make the method work properly. Our object was placed on a turntable plate in the lightbox to ensure an even lighting. The lighting is of crucial importance since any deficiencies would be passed on to the 3D model in the processing stage. We also placed our camera on a tripod to avoid any unnecessary movements. Once we had taken the required amount of images, we moved on to the processing stage.