POV-Ray - Tips

[micheus]

I'm going to let here some information about the Lights and Render dialogs which can be a start point for someone creates their settings.

It's not a technical information. For that, please, take a look at the POV-Ray 3.7's Reference Table of Content. It explanes in details how the light works in POV-Ray.


Render dialog



The most common elements to be changed are in General option, Lighting and Camera tabs:

• General option
  • Subdivision - allows to smooth the object before send to the render, instead of do that in the Wings3D project if we are working with a low poly object;
    
  • Export UVs - should be checked if any material has UV map assigned;
    
  • Export Normals - checked by default, but if omitted POV-Ray will compute it by it self. It can reduce the file size, but you have no 100% guarantee it will be using the same values as Wings3D;
    
  • Transparent Background - the background colour will be replaced by a transparency. This allow us o create images that can be composed in other graphic editors. We must to choose a file format that uses the alpha channel (like: png and tga);
    
  • Background - defines the background of the scene - it's the colour that fills the environment;
    
  • Anti-Aliasing - used to refine the final image by smoothing jagged edges on curved lines and diagonals;
    

• Lighting
  • Photons - we can enable it and set our own Count value when our scene have materials like metal, glass or we enable the Atmosphere settings. Very higher values give us better results in caustics and reflections, but it also increases the render time - it's a good idea increase values like this for the final render only;
    
  • Subsurface Light Transport (or Subsurface scattering) - must be enabled when we enable this property in a material;
    
  • Radiosity - it will give the image a better look by using the environment settings and increasing the illumination of the scene. Usually the Normal preset option give us a good result. We also need to enable it if we want the caustic effect to appear;
    

• Dimension - we can choose a predefined dimension from the preset list or enter with a customised one;
  • Camera
    

The lights properties can be accessed in the Outliner window, expand the Lights node, select the light and in the context menu select Property.

Area light dialog

The area light is one of the lights that will allow us to add soft shadows to the scene. The appearance of the shadows produced by this light will depend on a set of factors like its dimension, number of the light matrix (default is 2x2), and others.

• Power - will be an influence for any kind of light. If a scene has a couple of lights, we may need to decrease power in order to balance the scene lighting;
  
• Photos - if our scene will requires we to enable photos on Render dialog we probably will enable it here too;
  
• Size - defines the light matrix. The panel size is defined by the object on the geometry window and it's manipulated just like a regular mesh object;
  
• Adaptive mode - it will enable the checkbox following it. For a better shadow result we usually will enable it and Jitter at least. The different mode usual don't change as much the result - so, I use to select Adaptive 1.
  

Here is a sample scene with differents parameters of an Area light added progressively (see yellow note on each frame):


and here, the same scene - using the settings on the 4th frame, but now with an array of 10x10 - plus the basic Render parameters we can set to improve the result. It was rendered without and with Radiosity enabled. Notice the background colour has also influence on the scene lighting:


* More to come when I have some free time.