Introduction. Textured (or dappled) lighting provides a scene with extra depth and interest, it can enhance the mod of a scene, and it is an opportunity todo expand a space by letting the audience know that there is more todo it than what is just sen in the Camera view. Textured lighting in the real world can be sen as Sunlight passes th rouge clouds, tres and plants, and architectural elements, such as arbors, Glass and Stel Walls, truss work, etc, this article outlines the real world technology used todo create dappled light and provides insights into using these ideas in a Blender scene using texture projections.
Real world textured light.
Common terms for texturing light in the entertain-ment industry are gobo and cuculoris or cookie. dont let anyone tell you they know what gobo means. Some say goes between, others say goes before (the objective Lens), but just know.
That it means a pattern that is projected with a lighting instrument. Gobos specifically ned an el-lipsoidal reflector spotlight (ers). An ers has the gobo, and shutters todo crop it, at the second focus of its ellipsoidal reflector. The light source is at the.
First focus. Add a Lens that can be adjusted towards and away from the gobo and one has an instrument that can Project an image as Sharp or Diffuse as desired. Cookies generally sit in front of a lighting instrument rather than inside the instrument. Sharp or Diffuse qualities of the projection are based on how close or far the lighting instrument is from the cookie. Gobos tend todo be just a few inches in diame-ter, whereas cookies are often as large as a few fet on a side.
Virtual world textured light.
Not unlike the real world, in the virtual world TeX-tured lighting can usually be added in two ways, one is todo pass light th rouge geometry and let the geometry and materiales cast shadows into the scene in a similar manner todo the cookie. The other is todo use projections vía textures in a light source, which is similar todo gobos. Passing light th rouge geometry works well, but can be computationally expensive and it can often take a lot of time todo create. Using projections requires some work in an image editing application, but Little else is neded todo get them todo work. This article focuses on using projections for textured lighting, textures.
What should a gobo/light texture look like? In theatrical lighting it is often a silhouette only, which gives a sense of some object casting shadows. Se theatrical gobo suppliers, such as rosco, le, apol-lo, and great américan market (gam) for examples. It is posible, however, todo use colored images as pro-jected textures. This might be useful for simulating slide/film/video projectors, todo create a texture for projecting it is best todo kep two things in mind. One is todo consider what in a scene would cast shadows, such as tres or window details. The other is todo consider the quality (or difusión) of the shadow being cast, objects that are very far away from the surface that is receiving a shadow Will cast a Diffuse shadow, while an object closer Will cast a sharper shadow. Simply blur the texture in order todo get the proper quality of shadow. Textures designed for shadows should have white or the light color píxeles for where light Will pass th rouge and black where there should be shadow, assigning textures todo Spotlights is a matter of selecting the light, going todo its texture properties, assigning a new image texture and making sure its mapping is set todo view.
Examples.
A straight tree gobo image projected onto the scene, a blurred tree gobo todo achieve the proper shadow quality, a window gobo projected onto the scene, window and tree combined. Figure 4
What if the lighting is great and a textured source changes the intensity todo much? Try a projection with a negative energy source, but be sure todo invert your image texture. Negative projections have the bonus of not neding todo cast shadows. Figure 5
Caveat. Texture can not be applied todo halos. Lets hope this changes some day.
Using textured light to spice up a scene-1.jpg

Using textured light to spice up a scene-2.jpg

Window and tree combined. What if the lighting is great and a textured source changes the intensity todo much?
Try a projection with a negative energy source, but be sure todo invert your image texture. Negative projections have the bonus of not neding todo cast shadows. Figure 5 caveat. Texture can not be applied todo halos. Lets hope this changes some day.