By default, Zendir Editor (and Zendir Studio) create the entire Solar System in the Universe. This means that all bodies are initialized and their data (position, rotation, velocity) are all loaded correctly from the SPICE kernels. NASA provides the SPICE library as a way for pulling updated ephemeris data from a particular epoch for Solar System bodies. Along with the 8 planets (Mercury to Neptune), the following three bodies are also added to the simulation:
- Sun (Sol)
- Moon (Luna)
- Pluto
NOTE
Currently, additional moons and celestial objects cannot be added to the simulation. Future releases plan to add these objects to the Solar System.
Configuring the Solar System
When configuring the Universe, there is an option to change the central body, also known as the zero base. This defines the origin of all coordinates within the simulation. By default, the Earth is the central body and will be positioned at the origin (). Changing this coordinate origin will not affect the rest of the simulation, as all positions are relative, but may help with spacecraft coordinates. If the spacecraft should be in a sun-frame, the central body may be changed to be the sun. Typically, for single-spacecraft simulations, it is best practice to set the central body to be the object that the spacecraft is orbiting.
The epoch of the simulation can also be configured to control when the start of the simulation begins. The default value is 01/01/1600 00:00:00. Input UTC now for the epoch to set the current time in UTC time.
WARNING
Avoid changing the zero base during a simulation. If the zero-base is changed, although all planets and SPICE data will be updated, the spacecraft will not change its position and will result in an incorrect orbit. Zero-base and other Universe functions should only be set before all other objects are spawned into the level.
Earth Clouds
The standard Earth models have an overlay texture of clouds that are present in the model. The clouds currently are not simulated and are a standard texture that rotates with the Earth’s rotation. However, the cloud density and opacity can be changed through a function call. The function Configure Earth Clouds can be called at any time to enable or disable the clouds on the Earth. The Opacity fraction will adjust how much of the clouds are transparent while decreasing the Cloud Contrast fraction will increase the amount of cloud cover over the Earth. The Normal Intensity changes how the normal map of the clouds affects the world.
Lunar Height Map
Most bodies in the Zendir System’s Solar System are made from spheres (or at least a high-polygon sphere). An updated height map has been added to the moon which can highlight the craters and mountains present on this body. This map deviates away from the sphere model and provides extra detail when rendering objects near or on the Lunar surface.
