Yesterday i was playing around with the V Ray sun light! i some times i can not seem to get the light positioning right so i tried out using the sun expression that comes with Cinema 4D.
I have created a little test scene you can play with the lighting and get quick renders! but i have also left the buildings in there to see what the sun looks like with larger detailed objects.
The Sun Expression has most of the real world values latitude and longitude along with the date & time.
Above shows a little guide i have made the time is set to around 1:30 in the afternoon and the coordinates are supposed to be set to the north pole.
Latitude 90, 0 , 0 N
Longitude 0, 0 , 0 E or W
I wouldn’t say that the guide i have made reflects real world positioning but if it helps you then that good to me!
Please let me know if it helps you!
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The V Ray sun parameters basically what they do!
Turbidity - this parameter determines the amount of dust in the air and affects the color of the sun and sky. Smaller values produce a clear and blue sky and sun as you get in the country, while larger values make them yellow and orange as, for example, in a big city.
Ozone - this parameter affects the color of the sun light. Available in the range between 0.0 and 1.0. Smaller values make the sunlight more yellow, larger values make it blue.
Water vapour – aqueous vapor, is the gas phase of water. Water vapor is one state of the water cycle within the hydrosphere. Not used in current version.
Intensity multiplier for Phys Cam - this is an intensity multiplier for the Physical Sun. Since the sun is very bright by default, you can use this parameter to reduce its effect.
Intensity multiplier for Std Cam - this is an intensity multiplier for the Physical Sun. Since the sun is very bright by default, you can use this parameter to reduce its effect. This multiplier affects only on Cinema4D Camera render, even if it have VRay Physical Camera Tag on it.
Size Multiplier - this parameter controls the visible size of the sun. This affects the appearance of the sun disc as seen by the camera and reflections, as well as the blurriness of the sun shadows.
Photon emit radius - determines the radius of the area, in where photons would be shot.
Photon emit distance - determines the distance of the area, in where photons would be shot. This area is represented by the green cylinder around the Sun’s ray vector. This parameter has effect when photons are used in the GI solutions or caustics.