| Now that you understand the basics of Final Gathering, you could start pushing for extreme photo-realism. |  |
Notice how Final gathering tends to give dull looking images. The hot spot (specularity) in the material of objects is not rendered because the light in the scene is not considered also transparencies and reflections are ignored. With XSI, we could use conventional ray tracing along with the Final Gathering algorithm on a single pass.
Let's assume we have a simple scene with FG.
The light's position is not important for FG because it is only necessary to fire off the photons for the effect. In this case we will move it where the primary source of energy is, which is the cube on top in this case.
Usually FG requires no color on the light but in this case add just a touch of color so that it will now affect the scene but not enough to upset the FG look.
The specularity will shine on materials that use specularity such as phong, but barely, because the light hardly shines. To compensate, exaggerate the specularity on the objects in order to be able to see the shiny effect.
The specular is now apparent.
Why not push it a little more and add shadows, enable shadows on the light, why not use the area lights feature for smooth attenuated shadows.
Add some reflection to both objects. For added photorealism you may wish to add gloss and samples. Gloss, fades the reflection according to distance as in the real world, samples controls the sampling to avoid the grainy feel.
Click here for the XSI 2.0 scene. This image is rendered in under 20 seconds on a below average speed computer. Beat that Arnold !.
Tutorial made by: Manny Papamanos