How to use the Corona Camera?





What is it?


The Corona Camera can be used instead of the native 3ds Max cameras (Free, Target, Physical), and should be used instead of the obsolete CoronaCameraMod modifier. It can be added from the Command Panel > Cameras > Standard menu, and it features all the photographic controls that can be found in a native 3ds Max Physical Camera, plus all the Corona-specific post-processing, panorama, VR, and other options. 


Note: The CoronaCameraMod modifier is still available in 3ds Max to guarantee backward compatibility for scenes saved with older versions of Corona Renderer. It should not be used in any other cases, though.



The Corona Camera can be created by going to Cameras > Standard. There is no separate "Corona" category (this saves you one click). 




What are the advantages of the Corona Camera?


Depth of Field

Depth of Field can be easily toggled on and off from the Corona Camera’s UI, and the focus can be set by picking any object in the scene using the Override focus > Object option. The selected object’s pivot will be used to determine the position of the focus point. This is especially useful if the focus should be locked on a moving object during animation.


Depth of field can be enabled for the Corona Camera, and the focus point can be locked to the pivot of a specific object. 



Object Visibility

The Corona Camera has the ability to include or exclude objects in the view rendered from that specific camera. This removes the need to use the “Renderable” object property, and also allows rendering different objects from different cameras.


Specific objects can be excluded from Corona Camera's visibility. This is a per-camera setting, so you can make different objects appear and disappear in different cameras.



Interactive Rendering

As opposed to the native cameras, Interactive Rendering will not restart when changing the tone mapping parameters of a Corona Camera.



Virtual Reality and Panoramas

VR, panoramic, and fisheye projection can only be enabled when using the Corona Camera. They can be found under the “Projection & VR” rollout.


The Corona Camera features various projection modes. 



Additional Features

  • You can select both the Camera and its Target at the same time by clicking on the connecting line.
  • You can see the Camera’s clipping planes in the viewport.
  • You can easily resize the Camera’s viewport icon using the Icon size option under the Viewport display rollout.
  • The camera's viewport icon changes according to the currently used VR mode (spherical, cylindrical, etc.)




Exposure, tone mapping, post-processing and Corona Camera


Adjusting exposure, tone mapping, and post-processing options:


When rendering outside of the Corona Camera (e.g. from a free perspective view):

  • The exposure, tone mapping, and post-processing settings available under Render Setup > Camera and inside the Post tab of the Corona VFB will be always used. These settings are locked to each other, so if you change a setting in the Render Setup dialog, the same value will be used in the VFB, and vice versa.


When rendering from a Corona Camera:

  • If Use global exposure is selected under Photographic parameters of the Corona Camera - the image exposure is determined by the exposure settings available under Render Setup > Camera and inside the Post tab of the CoronaVFB.

  • If Use simple is selected under Photographic parameters of the Corona Camera - the image exposure is overridden by the Corona Camera. Exposure settings available under Render Setup > Camera and inside the Post tab of the CoronaVFB will be ignored.

  • If Use photographic (ISO) is selected under Photographic parameters of the Corona Camera - the image exposure is overridden by the Corona Camera. Exposure settings available under Render Setup > Camera and inside the Post tab of the CoronaVFB will be ignored.

  • If any Override checkbox is enabled next to any of the settings inside the Corona Camera's Tone mapping and Postprocessing rollouts - those tone mapping and post-processing settings will be overridden by the Corona Camera, and tone mapping and post-processing settings available under Render Setup > Camera and inside the Post tab of the CoronaVFB will be ignored.

The Override checkboxes specify whether the Corona Camera's or the global VFB/Render Setup settings should be used. 



If the VFB Post tab is greyed out, it means that those settings are overridden by a Corona Camera or by the CoronaCameraMod modifier. 

You will see a short note in the VFB explaining why it is so. 




Saving and loading the tone mapping and post-processing settings


The Corona VFB offers Save and Load options, which can be used to save and load tone mapping and post-processing settings using the special CONF file format. Starting from Corona Renderer 4, those settings can be freely exchanged between the Corona VFB and the Corona Camera. This allows, for example, for:

  • Defining the look of the image using the Post tab of the Corona VFB, and then moving those settings to a Corona Camera.
  • Creating various post-processing presets, which can be then loaded into different Corona Cameras and the Corona VFB.
  • Setting up multiple Corona Cameras with different post-processing settings, and then loading those settings from one of them into the VFB.




The Corona VFB's Post tab features various tone mapping and post-processing options, and the possibility to save and load them. 



After clicking the Save button, you can save your custom preset as a CONF file. 



You can then load the CONF file into a Corona Camera (and vice versa). 



If the CONF file is loaded into the Corona Camera, and the Override checkboxes are enabled in that Corona Camera (to override the VFB settings), you will see that our custom post-processing preset is now used for the rendered image. So first we set up our desired post-processing in the VFB, then we saved them as a CONF file, and then loaded that CONF file into the Corona Camera.



If we render a non-camera view (in this case a free perspective view), only the settings available in the VFB Post tab will be considered. Once we render from the Corona Camera again, the CONF settings loaded in the that Corona Camera will be used again. 



See also: