This chapter discusses the concept of Auxiliary Tools in depth perception. Four recent techniques are considered, that apply the concept in the domain of liver vasculature visualization. While an improvement is evident, the evaluations and conducted studies are found to be biased and not general enough to provide a convincing assessment. The chapter provides background information about human visual perception and a brief history on vascular visualization. Then four state-of-the-art methods are discussed. Finally, a comparative discussion points out objectives for future follow-up work.
Keywords: Depth enhancement; Depth perception; Medical visualization; Non-photorealistic visualization; Vascular structures.