Full error message text:
"PRG Clear Sky" model was selected, however an old version of the required data is installed. The lowest rendered solar elevation will be limited to -4.2 degrees.
Map with the problem: "map name"
Corona 12 comes with a new version of the PRG Clear Sky model with extended range of solar elevations, thanks to which you can render accurate sky with sun down to -12 degrees below the horizon. The model data is stored in C:\Program Files\Corona\prgSkyModel
In rare cases, a newer version of Corona may be loaded with the old sky model data without the -12 degree solar elevation support. This can happen, for example, in the following scenario:
- You are using multiple host app versions (3ds Max or Cinema 4D)
- You install Corona 12 for all your host app versions - this installs the new sky model data
- Then you install Corona 11 or older for a specific host app version only using the custom installation mode - this overwrites the new sky model data with the old one
As a result, when you launch any host app version with Corona 12 installed, it will be using the old sky model data. You will see the error message and you can safely continue working, however the solar elevation will be limited to no less than -4.2 degrees.
Note: an opposite scenario can happen too (using Corona 11 with the new sky model data). In such case, no error message is displayed and you can continue working normally. The limitation is the same - the solar elevation will be limited to no less than -4.2 degrees.
Solutions:
- Use multiloaders (3ds Max only) - this is the best solution for launching 3ds Max with a specific Corona version. The old vs new sky model data issue will not appear when using multiloaders.
- Always install the older version of Corona first, and only then the newer version. This way, the new sky model data will always be used and no error messages or issues will appear.
- Manually swap the sky model data in C:\Program Files\Corona\prgSkyModel depending on which version you would like to use. When using the unpack option in the Corona installer, the sky model data is unpacked to <unpacked directory>\Chaos Corona\Corona\prgSkyModel.