Week 4 - (Maya Lights)

As part of achieving an overall understanding of lighting I naturally wanted my initial experiments to be just focused on fundamentals. For this week my goal was to explore the effects of the six Maya lights and how they worked uniquely within the program. As A bonus I also looked into some specialised lighting attributes. The outcome of the actual goal was to hopefully help me get a better understanding of lights, and how I could best use them to build an environmental light rig. 

In preparation I checked out a DVD on lighting effects. From it I was able to drag out certain aspects of lighting attributes that I had not thought of. This included the knowledge of caustics, producing unique shadows from light mapping and optical effects (ie, lens flare). I also learnt about IPR Rendering.  

METHOD

The main focus on producing accurate results for the testing was to create a control scenario. My original intention was to use both the Environmental Park and Refinery in order to use for the testing. The problem with this was mainly the Ludacris nature of using an entire environment to get the effects on one light. The space may have not given an accurate result and could have been hard to read. This being said I never actually allowed myself time to test this, but was already happy with the testing area I created. Though in all future experiments the actual control environments will be used.

 

Default Lighting

Part 1

The Control environment I used to host the lighting was a simple inversed cube. The lights used would always be set up in the same position unless otherwise (ie, volume light). Each light would emit against a corner area and show 3 examples with different attributes.          

RESULTS

The following information is derived from subjective observations and read information.

Ambient – This felt like an extremely tinted light source that filled everything evenly. It had a sense that it could control the overall visibility of an environment and possibly the temperature as well. Ambient shade gave a strong sense of an AO like effect and adding appealing contrast.   

Directional – Did not really have that many adjustable attributes and might seem limited in terms of use by itself. With the combination physical sun and sky the directional light produces new attributes to help it become more controlled and varied.  

Point – Having a light source that can produce light from within a center point can probably be used for artificial light sources and for creative lighting. The distance for a point light isn’t that limited. Having decay helps remove distant Omni lighting that would give similar effect to an ambient light.   

Spot – Spot lights can help highlight particular areas and bring out a focal point. The cone angle adjusts the size of the circular light shape. Penumbra effects the edge softness of the light shape. Drop off effects the decay of the light shape.   

Area – Projects a 2D light shape depending on the size and shape of the light. Has a strong drop off that requires a higher intensity for visibility. 

Volume – Produces soft light depending on the scale and shape. The penumbra can be directly manipulated via liner and quadratic graphs. This allows the fall off and edge softness to be more controllable.  

Part 2

This part of the experiment will focus more on the extra effects that are produced within light attributes. As a control for this the same cube will be used and a spot light will be demonstrating the effects (unless otherwise). To also get a sense of a scene, primitives have been placed. The actual details of the lights attributes (the controlled ones) can be seen in Light Chart 2. 

RESULTS

 The following information is derived from subjective observations and read information. 

Area Light – Produces appealing lighting and shadows. Dependant on the amount of high and low samples. Shadow mapping can also be altered with its sampling adjusted. More in depth research probably needs to be applied here as technical understand of light and sampling seems to be its focus. Also takes a bit of effort to render as increased sampling increases render time.  

Light Effects – Used to create different kinds of optical effects that are the subject of lens reflection/refraction (i.e. lens flare). Is produced by having a point light on camera and set to have ‘illuminates by default’ turned off. More of an effect that can come into play with establishing time of day with environments. Extremely customisable to appropriate with the kind of camera that might be used. For some reason it only works in Maya renderer and not Mental ray. 

Light Mapping – Simply applying a file onto the light map. Can create interesting shadow effects as well as caustic effects. 

Overall the main things that were leant was the breakdown of light attributes and how certain lights effect areas differently. With the understanding of this information more effective and educated decisions can be made in development of environmental lighting rigs. There have been a few things during this experiment (i.e., area lights) that I have had some uncertainty about. However I going strive to continue to pick up other light features that I may not have figured out.

References

Hackett, D. (2012). Area Lights 101. [Online] Available

http://elementalray.wordpress.com/2012/03/19/area-lights-101/ [October 16th 2013]

Naas, P. (2010). Maya Light Types. [Online] Available

http://www.paulnaas.com/canada/mart421/handouts/lights.pdf [March 31st 2010]

Splicer, M. (2012). Lighting in Maya. [Online] Available

http://www.cse.ohio-state.edu/~parent/classes/682/WI12/TechReports/lighting.pdf [January 24th 2012]

Multimedia

Rendering 3: Light Effects
       [DVD]. (2004). Holywood,CA: Gnomon Workshop.