File Format: cytherea.jpg - Full colour 1440x720 JPG file, 817K.
Map Type: Simple Cylindrical Projection.
Map Origin: Constructed by Constantine Thomas, derived from 'flooded' Venus heightfield created using DEM data from Magellan GxDR CD-ROMs (JPL/NASA).
Map coverage: Full 360° wrap (centred around 0°), full pole-to-pole coverage (Cytherea has no polar caps).
Image coverage: Vertical edge: 180°W. Horizontal edge: 90° N/S.

Radius (1 km = 1 POV unit): 6,051 km
Average distance from primary (1 km = 1 POV unit): 105,000,000 km

NOTES: Here's how I constructed this map: I rendered a global topography map of Venus as a heightfield object viewed from high above with a shadowless light source behind the camera, and a blue plane (the water) set at a water_level of 3 km. I then projected my Earth cloudmap over it (still rendering onto a planar surface) to create the final map. Note that the land colours aren't real, they're just a POV texture (Rusty_Iron) added for a bit of variety. In other words, the map construction was all done entirely within POVray!

I have now posted the topography map that I used (see left) - white is high, black is low. Note that although it's not 1440x720 pixels it will still render in the correct proportions. Also note that the original DEM contained data gaps (black stripes) which have been filled in here using data cloned from other parts of the map. Note that you can use this as a normal_map for the landmap to bring out the mountains and valleys on the terminator!

File Format: cyth-png.zip - Four 256 colour land/ocean/cloud/cloudbump 1440x720 (Clouds are 2048x1024) PNG files in a single 1.90 MB zip file.
Map Type: Simple Cylindrical Projection.
Map Origin: Constructed by Constantine Thomas, derived from 'flooded' Venus heightfield created using DEM data from Magellan GxDR CD-ROMs (JPL/NASA).
Map coverage: Full 360° wrap (centred around 0°), full pole-to-pole coverage.
Image coverage: Vertical edge: 180°W. Horizontal edge: 90° N/S.

Radius (1 km = 1 POV unit): ocean map: 6,051 km ; terrain map: 6,051.1 km; cloud map/bump: 6,053 km.
Average distance from primary (1 km = 1 POV unit): 105,000,000 km

NOTES: The four maps on the left (land, sea, clouds, cloudbump) are designed to be combined in POVray to create a Cytherea with ultra-realistic oceans and clouds. They are available here in a single 1.90 MB zip file called cyth-png.zip. The PNG files are smaller than gifs (and therefore easier to download!), and are fully supported in POVray so you should have no trouble using the maps. A sample scene file (cytherea.pov) is provided with a full explanation to show you how to use the maps. All four maps are the same resolution as the basic Cytherea map described above, but have 256 colours instead of 16 million.

The idea is to layer the maps to get the right effect. The sea map goes at the bottom of the pile, and is given a specular finish. The land map goes above this - the blue areas on it that correspond to the oceans are set to complete transparency by a transmit statement. You will thus be able to see the specular ocean map beneath, but the land areas will 'cover over' any specular highlight on the sea map. Thus, only the ocean regions of Cytherea reflect the sunlight specularly, and the continents do not (which is what we want). The blue cloud map then goes on top with a complex transmit statement (see scene file) that allows you to see through the clear parts and gives the rest of it a varying opacity. Finally, a greyscale cloudbump map is used as a normal_map to simulate high clouds on the day/night terminator. Note that the cloudmaps are the same ones used for Earth. A sample scene file (cytherea.pov) is included in cyth-png.zip to demonstrate and explain how to combine the maps.