Tone and Gamma correction

Large studios know that any 3D CG rendered image must be tone corrected before putting them to film. But several independent 3D CG artists don't know that and publish their 3D CG rendered artwork as they come out of the renderer and wonder why their images look so much CG. This tutorial explains what are tone and gamma corrections, where does that comes from and why tone correcting 3D CG renders is necessary and how to take that step into consideration in all stages of 3D CG image production.

Lighting tutorial

Lighting a scene is more than putting a few lights in the scene and rendering. A lot of additional lighting settings must be thought of and fine tuned. This tutorial is not about the standard 3 lights setup. It is about types and characteristics of CG lights, types and quality of shadows, faking radiosity by adding ambiance and bounce lights.

Using A:M's Photon Mapping

Photon Mapping is a rendering technology that simulates bounced indirect lightings in a scene. But Photon Mapping can easily take very long to render if the parameters are not set in an optimal fashion. Proper setting of Photon Mapping parameters can be difficult if done by trial and error. This tutorial tries to explains the effects of the numerous parameters which controls the operation of the Photon Mapping and give some rules of thumb for guessing good starting parameters.

A:M, Photoshop and alpha images

This tutorial explains all you need to know about alpha channels, what they are and how they are used, in order to use Photoshop to produce alpha images for decals or to composite A:M alpha rendered images in Photoshop. No more white halos in your decals with alpha channels and no more black halo in your Photoshop composited 3D CG renders.

A Wood Waterial using Native A:M Combiners

One of the most recurring questions for A:M users is "How can I use the Material builder in A:M?". Here are some hints. This step by step tutorial explains the concepts of combiners, noise functions, hierarchy of material nodes, turbulence, bump materials, using poses or actions to control material colors and positioning in order to get variety out of one single material.

Materials and Noise Functions

Some A:M combiners such as Fractal Sum, Perlin, Sine and fBM are based on Noise functions. They are used to produce terrains, cloudy skies, organic textures of all king including marble, wood grain, etc. Here are some more information about those Noise Functions, what they are, the parameters that controls them, what is the octave and how to set all those parameters to get the noise function that will fit a given application..

Skylights

Since the recent (this tutorial was written around year 2000) release of some "Arnold" renders, skylights seems to be all the rage. That is because they offer a decent alternative to Global Illumination. But after producing yet another "à la Arnold" image, what's next? This tutorial explains what are skylights andhow to build and use them. It also explains advanced techniques using skylights in combination with image mapped transparent skydomes. A skylight library is available for download.

Stereo renderings

Finding proper parameters to render a stereo image can be made easy because the process is rooted in easily measurable parameters from the real world like what will be the viewing sizes and distance of the stereo render. Then, given an average human eye-to-eye distance and a little math, it is easy to get the proper stereo rendering parameters that will give the planed visual results.

Beveling models

Beveling can significantly enhance the look of 3D models. Bevels catch highlights and shadows and adds lines of shading that separate different planes of the same model. It also adds realism because real world objects do have bevels on their edges. Ultra sharp edges are only seen in 3D CG images and is a sure way to give the CG origin look. By using already beveled primitives, the task of modeling complex beveled objects is greatly simplified. This tutorial shows how to add bevels to object edges and how to use beveled primitive. A library of beveled primitives is also available for download.

Mapping a firmament

Mapping a starry sky map onto a sphere is a little bit more work then simply using the spherical mapping method. Stars in a starry night sky are tiny points of lights that should all look more or less the same size and intensity. However, the spherical mapping process will pinch the map at the pole and the stars will disapear. This tutorial demonstrates a different method to map a sphere while preserving as much as possible of the original map pixel dimensions and shows how to do manual flatening.

Understanding Animation Master CP bias properties

Gamma is one of Animation:Master CP bias property, It controls the curvature of the surface at the CP position. One rarely needs to adjust Gamma values for CPs in a model but when needed, it is better to understand how they work and what may be the affter effect when tweaking them especially when the model is designed to be used in animation.

NOTE: The above Gamma tutorial applies only to A:M v9.5 and older. Starting with v10.5, handling of modified Gammas during animation is way more robust and does not produce poping during animation anymore.