Abstract: A method for conditioning of surface-based geological models is provided. Surface-based geological models seek to represent a portion of the subsurface while honoring the available data. However, conditioning of surface-based geological models may be challenging particularly for situations where the geologic elements, such as lobes or channels, are interspersed with another geological element, such as impermeable mud. To condition the geological model, muds are specified through a mud trend or a set of specified mud layers. For example, each mud layer provides the environment of the geological element, such as the lobe to rest on or the channel to erode into. The surface-based geological model may then be built by sequential conditioning layer by layer, such as bottom upward. In this way, the mud layers provide context in which to place objects during conditioning to better generate the surface-based geological model.