Modelling the Lunar Surface

Alan Murta, James Miller and Simon Embley

Introduction

This page describes an exercise in applied geometrical modelling - generating an approximate graphical representation of the lunar surface. It combines spectral synthesis methods and stochastic feature generation rules with map and table-based descriptions of actual lunar topography. Considerable attention has been paid to level-of-detail issues and the consistent fusion of synthetic and map-based features. Lunar forms currently modelled include mare and terra terrain types, mountains, rilles, ray systems and a variety of crater types.

Surface overview

Last quarter

Full moon

First quarter

The three images above show the near-side of the moon viewed from an altitude of 3,500 km. The longitude of the sun for each image is respectively 90.0W, 0.0E and 90.0E. Any image may be clicked on for a higher resolution version.

Silicon Graphics' GL was used to render the images, using a local illumination model with no self-shadowing. The incorporation of effective shadowing methods should significantly improve the appearance of surface features under oblique lighting conditions. The model generation time for each image is around one minute, with rendering taking 15 seconds on a 200 Mhz Indy.

Detailed views

The Apenninus mountains viewed from 100 km above the Mare Imbrium

The crater Plato viewed from 300 km above the Vallis Alpes

An eastward view of the Apollo 11 landing site from an altitude of 25 km

The images above give a more detailed view of a variety of lunar features. A fractal surface generator adds detail as the viewing altitude is decreased. A random (but deterministic) crater population is also added to the surface.

A paper which describes this work is available for downloading (compressed PostScript).