Against Immateriality: 3D CGI and Contemporary Art is a practice-led research project exploring three-dimensional computer-generated images (3D CGI), still and animated, as a mode of artistic expression. A post-photographic image paradigm that is habitually associated with soft power, spectacle and commodity forms, in recent years 3D CGI has emerged as a compelling way through which artists might express, represent and comprehend the effects of digitisation on art and life. Across three thematically linked but distinct chapters—Materialising, Corpsing, and Becoming 3D—I argue for the cultural, social and political realities associated with 3D CGI, investigating its unique characteristics as a sensual, multi-perspectival mode of image, object and world building. Through an exegesis of my own artistic practice, one in which I produce 3D computer-generated artefacts before translating them into physical objects and spatial installations, I examine the conditions of 3D CGI production, presentation and dissemination. I contextualise this practice within a broader movement within contemporary art of artists that use 3D CGI to comprehend and interrogate digital culture, analysing artworks by Mark Leckey, Ed Atkins, Sondra Perry, and the research group, Forensic Architecture. Each of these diverse examples provides a distinctive perspective on the implications of this mode of digital image making, including its role in refiguring notions of embodiment and materiality, how it can be used to vision aspects of contemporary society that are often occluded, and its ability to (re)construct images of traumatic pasts, turbulent presents and speculative futures. Ultimately, I argue that 3D CGI allows for reflection on and critique of digital technologies by underlining their immanent materiality and the lived, bodily effects these so-called immaterial images have the power to produce.