# Viewport settings

This page of the application settings dialog contains options related to the interactive viewports of the OVITO.

## Camera

Coordinate system orientation

  OVITO can restrict the viewport camera rotation such that the selected Cartesian coordinate axis always points upward. Default: z-axis.

Restrict camera rotation to keep the major axis pointing upward

  This option constrains the camera’s orientation to prevent the camera from turning upside down.

## Viewport background

This option changes between a dark (default) and a white viewport background.

## 3D graphics

Graphics hardware interface

  Selects the application programming interface used by OVITO for rendering the contents of the interactive viewports. Currently, OVITO supports the graphics interfaces OpenGL and Vulkan (latter only available on certain platforms). The OpenGL-based viewport renderer is more mature and should work well on most systems. Vulkan is a more modern programming interface, but some graphics drivers still exhibit compatibility problems. Please inform the OVITO developers about any problems you encounter on your system.

  The Vulkan interface provides the advantage of letting you explicitly select the graphics device OVITO should use if the system contains more than one GPU or integrated graphics unit. In contrast, you have to make the device selection on the operating system or graphics driver level when using the OpenGL interface.

  Note

  The Vulkan renderer option is not available on the macOS platform or in OVITO for Anaconda builds.

  Note

  The Vulkan renderer has been temporarily removed from OVITO in release 3.9.0, because major changes were made to the internal scene rendering system. We intend to add Vulkan support back in once the Vulkan renderer code has been ported to the new programming interfaces and all issues have been resolved. Please contact support@ovito.org if you have any questions.

  Select System Information from the Help menu of OVITO to access further information about the graphics hardware found in your system. Please attach this information in case you report any graphics compatibility problems to the OVITO developers.

Transparency rendering method

  This option affects the rendering of semi-transparent objects when they occlude other objects or overlap with each other. Both available rendering methods represent different approximations of how a true rendition of semi-transparent objects would look like - which is not achievable in real-time visualization using OpenGL/Vulkan.

  Back-to-front ordered rendering (default) gives correct results if there is only one kind of semi-transparent object in the scene, e.g. just particles, but likely fails to render a mixture of different semi-transparent objects correctly, e.g. semi-transparent particles combined with semi-transparent surface meshes.

  Weighted Blended Order-Independent Transparency is an alternative method more suitable for overlapping semi-transparent objects of different kinds. But it delivers only a rough approximation of translucency.