Update_v1.1

With latest v1.1 update, we added : a full new shading node, romboReflectRetro full PBR support to the Glints node custom map support for the Glints node automatic fix for bad inverted normals for SSS-RW a new multiple scattering mode to ReflectMultiScatter a re-work of some internal code to be overally faster a new batch[…]

Retro-reflections

Retroreflection is an optical phenomenon where light scatters back to its source along the inverted incident direction. Materials with retroreflection properties are used for safety garments to help enhance visibility in low-light conditions like roads at night when illuminated by car headlights. Traffic signs and pavement markings also use materials with such properties to ensure[…]

Rough Diffuse

In our quest for an improved diffuse model we already seen a principled implementation and a super smooth lambertian sphere model. We’ll briefly see here a ‘microfacet’ lambertian model that comes with the DiffuseRough shading node. As before we don’t really need to fully understand all of this but a general understading is still better[…]

Skin Layers

SkinLayers material is a three layers SSS dipole implementation in the style of the old alSurface material with added features like ‘peach fuzz’ reflections and ad-hoc params to better control overall sss appearance. Works great for anything releated to subsurface scattering and remains super easy and intuitive to use. Here for this Judge Dredd’s caricature[…]

Lambert-Sphere BRDF

In our journey on diffuse shading we have seen how a diffuse principled implementation better suites modern workflows than the classical Oren-Nayar implementation. The main offender on the Oren-Nayar implementation (rombo DiffuseGeneralized, Arnold Std Material) is that it is based on single scattering and so it leaks energy (diffuse gets too dark with increasing roughness).[…]

Reflection Slope

Reflections are a complex matter. However we don’t need to fully understand them to be able to use them in a CG workflow, after all reflection slope for example is just a single parameter we may better grasp just looking at the different results we get while tweaking it. But we can still read the[…]

Interfaced Lambertians

Generally diffuse and specular lobes are layered making use of the Fresnel reflectance at the interface. This simply means that the diffuse lobe is multiplied by 1-Fresnel while the specular lobe is added on top. Practically it means that when Fresnel is at max (at grazing angles) we have only reflections showing up. This ensure[…]

Refractions

This shading node does refractions at boundary and then continue the ray into a volumetric medium with single scattering until it hits the back of the surface and it’s finalized into a new direction. This model is generally applicable to materials with low indices of refraction so that their translucent nature implies that a high[…]

Diffraction Lobe

Turns out that most computer graphics conductor materials (metals) don’t fit well with their measured real life counterparts. Looks like microfacet models (any reflection node you ever used..) can’t fully address the appearance of this kind of materials. Microfaceting theory models the appearance of a material at macroscopic level based on surface micro details. Situation[…]