Klein's current research interests lie in the field of computer graphics with emphasis on rendering, geometry processing and visualization. Specific topics in rendering are the digital appearance of materials, appearance capture, data-driven modelling and compression, appearance editing, global illumination computations, neural rendering, image-based and hardware-accelerated rendering. Research in the area of geometry processing comprises surface reconstruction, semantic enrichment of unstructured point clouds, 3D image and shape analysis and synthesis, morphological analysis, exploration of shape spaces and in visualization research concentrates on the visualization of complex biological and medical data and foundations of virtual reality including telepresence and teleportation.