NOTE: The latest version gives a couple of groups use of the new ‘ray depth’ feature, so you need a build from this month for everything to function properly.
WHY THIS COLLECTION OF GROUP NODES
-The idea is to provide a collection of standalone effects and materials through group nodes to allow people to quickly create common materials like glossies and glass without having to put together an entire node tree for every object. This would also tend to help those new to the Cycles engine due to premade nature of the materials where he only has to place one or more in the tree (perhaps mixing them together as well), and tweak a few settings to get the desired effect during rendering. The other part of the idea is to make the materials fairly generic so they could be used as or part of many different materials, something similar to what you see in the material systems of engines like Luxrender.
This was originally and still is mainly for my personal use, but my list of ideas may assume many different cases that would require a wide assortment of materials and thus more group nodes would be needed to cover them.
Download the .blend above, select append, select the .blend file, and select the node tree data type list to find the list of available group nodes.
One of them is known under the name ‘Light’, while we do have an emission node, the rationale for creating it is simple
Taking in part what Micheal W did to make a light invisible, it was clear that the possibilities of light control was more than just that and I wanted to create a node group to give maximum control over light objects and light materials. This node also greatly reduces the aliasing seen on edges that border a light material or intersect with areas of the image where a light object is by allowing you to ensure that the the maximum RGB value of the light material is less than one (sharply reducing the contrast between pixels which the multi-sampler would otherwise have trouble anti-aliasing)
Options for the light node:
LIGHT COLOR: - Same as the normal emission color
STRENGTH: - Same as a plain emission node
TRANSPARENT: - Make the light transparent, since you can’t create a boolean for a group node option, just set the value anywhere above 0 to make the material use transparency
FAC: - Allows you to tweak the visibility of the actual emitting surface without any changes to the amount of light emitted, a value of 0 would make it render as if it used a plain emission node, a value of 1 will make the light invisible if it’s set to be transparent or make the emission surface invisible and the base material visible if not, depending on the power of the emission, you may have to use very high values (lower than 1 but higher than 0.9) to easily see the base material (or a partial transparency if the light is transparent)
BASE_MATERIAL: - The base material seen through the emission surface if the Fac value is high enough, is a closure input so it accepts any closure node setup (which allows base materials from glass to rock to mirrors)
Hope you find it useful, it has helped me with my scenes.
Cycles_nodes_2_65.blend (3.79 MB)