Photometric Parameters
Learn about photometric parameters when raytracing in VRED. These parameters are used for measuring the perceived brightness emitted from a lightsource. Use it to model lights and render to see how they look in different environments, so you can configure them to your needs.
For additional information on photometric parameters, see the following:
Video captions: Open the Light Editor, via the item, Scene, in the main menu bar. Create a spotlight and position it freely above your geometry. Change the intensity to 10. The current intensity value of the spotlight isn’t able to be measured with physical values. The Intensity value is assigned as 1, and in our case is 10. Open the Render Settings with the help of the Quick Access Bar and call up options under the General Settings tab. To measure the brightness intensity of light with physical values, please activate Enable Photometric Parameters. You see a warning is prompted because Autodesk VRED tries to change all intensity values to physical values. Via Enable, all intensity values are changed, which can result in an alteration of the lighting. Should you ignore the suggestion, the values remain the same and are not adjusted to physical parameters, which darkens the image. Pick Adjust Values. VRED tries to retain the lighting as much as it can but changes the values to physical parameters. As you can see, there are now realistic physical values available for selection. Essential while working with photometric parameters, is the setup of a photometric camera. Open the camera settings, via the Quick Access Bar and select Physical Camera under Tonemapping in the Image Processing tab. Alter the FStop to 5.6 and the Shutter Speed to 8. Open the Material Editor and select your environment. Activate Mapping in the Color Correction section. Mapping means that the white value of RGB 1, 1, 1 is mapped to some value. An approximation of the value, 10 000 cd per square meter finds its application.
Find Enable Photometric Parameters in Render Settings > General Settings > Options. This changes the intensity values to physical values for altering the scene lighting. Try Adjust Values when changing to physical parameters. In the Camera Editor, select the Perspective camera, then Image Processing > Tonemapping > Tonemapping > Physical Camera to set up a photometric camera, then modify the FStop and shutter speed.