Performance
The performance of the application may vary significantly depending on the characteristics of your system. This chapter describes what are the factors that have an impact in a greater or lesser degree in the performance of the Gaia Sky and explains how to tweak them. It is organised in two parts, namely GPU performance (graphics performance) and CPU performance.
Graphics performance
Refer to the Graphics performance chapter.
CPU performance
The CPU also plays an obvious role in updating the scene state (positions, orientations, etc.), managing the input and events, executing the scripts and calling and running the rendering subsystem, which streams all the texturing and geometric information to the GPU for rendering. This section describes what are the elements that can cause a major impact in CPU performance and explains how to tune them.
Multithreading
Gaia Sky uses background threads to index and update meta-information on the stars that are currently in view. The multithreading option controls the number of threads devoted to these indexing and updating tasks. If multithreading is disabled, only one background thread is used. Otherwise, it uses the defined number of threads in the setting.
Limiting FPS
Gaia Sky offers a way to limit the frames per second. This will ease the CPU of some work, especially if the max FPS is set to a value lower than 60. To do it, just edit the value in the preferences dialog, performance tab.
Draw distance (levels of detail)
These settings apply only when using a catalog with levels of detail
like Gaia DR2+. We can configure whether we want Smooth transitions between
the levels (fade-outs and fade-ins) and also the draw distance, which is
represented by a range slider. The draw distance is a solid angle threshold against
which we compare the octree nodes to determine their visibility.
Draw distance slider in preferences dialog
Basically, the slider sets the view angle above which a particular octree node (axis aligned cubic volume) is marked as observed and thus its stars are processed and drawn.
Set the knob to the right to lower the draw distance and increase performance.
Set the knob to the left to higher the draw distance at the expense of performance.
Smooth transitions
This setting controls whether particles fade in and out depending on the octree view angle. This will prevent pop-ins when using a catalog backed by an octree but it will have a hit on peformance due to the opacity information being sent to the GPU continuously. If smooth transitions are enabled, there is a fade-in between the draw distance angle angle and the draw distance angle + 0.4 rad.