Render correspondence images.
parametric renderer for a Morphable Model, implements all useful Parameteric*Renderer interfaces
image renderer, controlled by RenderParameter, used for fitting
landmarks renderer, controlled by RenderParameter, used for fitting
renders masks (integer values) in image space, controlled by RenderParameter, used for fitting
generates a mesh in world coordinates, controlled by RenderParameter, used for fitting
generates a model instance in original model coordinates
Render correspondence images. Caches rasterization separately from shading.