T2S_illumination – x64 version released!

T2S_Illumination is a Softimage XSI shader dedicated to CG artists looking for a single Illumination node to be used as a basic building block for a great variety of materials.

This shader brings together different illumination models, as well as some of the last Mental Ray functions for optimized glossy scattering. New features, such as Coating surface effects, custom Lafortune settings, or Fresnel Mask are proposed here.

You can check our gallery to download free presets, or also get new T2S Files for custom materials.

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T2S File Format

In order to feed xsi shaders with physical material information, Tek2Shoot uses t2s file format to store different model parameters.

T2S files can store data for Lafortune model, IOR, etc. The goal is to be able to use real measurment data like Cornell university for BRDF to build preset files for our illumination shader.

Download the first pack T2S FilePack 01 - 11.15 KB. New packs coming soon…

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Iridescence with T2S_Coating

T2S_Coating adds a thin reflective coat to your materials, creating nice iridescent effects.

Thin Coats may be responsible of interferences in the reflected light, and let appear color fluctuations depending on light incidence.  Biological Iridescence can also be obtained by simulating mulitple layers, and calculating the ondulatory interference. These subtle effects can now be obtained in Mental Ray almost instantaneously.

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Lafortune Shader

The Lafortune representation is a BRDF model  (as Phong, Blinn, etc…) fitted to experimental values. It allows to create realistic specular with color fluctuation depending on the viewing / lighting angles. The T2S_Lafortune shader includes this model, as well as Oren-Nayar and Wrap Lighting for the diffuse component.

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Unexposed Mental Ray shaders (v1.1 – 32/64bits)

This xsiaddon file is a wrapper containing several unexposed Mental Ray shaders for XSI. The interface has been improved according to the Mental Image documentation.

These shaders are included : Car Paint – Ambient and FG Occlusion -  Glossy Reflection and glossy refraction – Physical Lights – D2S_Lights, which combines “physical_light”, “mib_blackbody” and “mib_cie_d” in order to reproduce realistic illumination, and last MR versions of “DGS_Material”, “Dielectric_Material”, and Volumetric Shader “Participating Media”

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Fresnel mask

The Fresnel Mask determines the reflectivity of a surface depending on its refractive index (IOR).

When used as a Mask on the reflectivity of a shader, the grazing-angles surfaces become more reflective than those facing the camera, adding realism to the material illumination.

Contrarily to other shaders (such as Dielectric, provided by XSI) the FresnelMask is based on the “real-physics” Fresnel Laws, and doesn’t have to be set arbitrarily.  Three mathematical models (Schlick, Fresnel and complex Fresnel) can be used to evaluate this function, allowing you allow to choose between accuracy and speed.

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