Techniques for generating a stereo image from a single set of input geometry in a three-dimensional rendering pipeline are disclosed. Vertices are processed through the end of the world-space pipeline. In the primitive assembler, at the end of the world-space pipeline, before perspective division, each clip-space vertex is duplicated. The primitive assembler generates this duplicated clip-space vertex using the y, z, and w coordinates of the original vertex and based on an x coordinate that is offset in the x-direction in clip-space as compared with the x coordinate of the original vertex. Both the original vertex clip-space vertex and the modified clip-space vertex are then sent through the rest of the pipeline for processing, including perspective division, viewport transform, rasterization, pixel shading, and other operations. The result is that a single set of input vertices is rendered into a stereo image.