Arnold: PowerMetal

We are designing a new Rombo.PowerMetal material. At the moment it supports STD generalized distribution for microfaceting reflections, microfacet normal mapping, multi-bounce microfaceting for correct energy conservation and rombo adaptive sampling for hard to sample highlights. STD distribution allow for both GGX(reflection slope set to 2) and Beckmann(set to 4) distributions and goes further on[…]

Arnold: Denoiser

Here we use non-local sample-based approaches together with feature-based filtering and adaptive sampling. A proof of concept on latest denoising tech plus some creative engineering that makes it work consistently for production. For example, with a little help from the camera and with Arnold in kinda ‘pathtrace’ mode (AA samples 4×4 while all others set[…]

Arnold: Fabric Shader

Yarn-based Cloth Shader : (aka) micro-fiber based BRDF : micro-fibers orientation returns correct physically-based macro specular highlights, suitable for both close-ups and distant views.   Automagic color shifting, normal/bumps simulated with specular roughness for improved detail and consistency. Here we see also fiber fuzziness in action.   Procedural weaving pattern support via WIFs (Weaving Information[…]

MILA Light Paths Support

Rombo materials come with automatic MILA light paths support. All you have to do is to enable them under Settings->Scene->Camera->MILALightPath. Here for example I enabled diffuse direct and indirect passes together with glossy reflection pass. This is the full beauty output (gamma corrected). These are instead the various pass outputs. Diffuse direct, diffuse indirect and[…]

Rombo.Skin Basic Parameters

Rombo.Skin comes with default parameters that are already good for realistic skin materials. Let’s see the basic parameters and their impact on skin rendering. Subsurface scattering profile. The function that describes how light enters an object, scatters around inside it, and then leaves the object is the BSSRDF, aka the bidirectional surface scattering reflectance distribution[…]

Sky Color Jittering

If you simply google for ‘sky banding’ you’ll find a lot of photographs that exhibit ‘color banding’ over the sky gradient. It’s not an inherent problem of rombo.skylight nor necessarily a problem related to the sky but just something that can be seen on any smooth gradient. If there ain’t enough bits to fully represent[…]

Multiple-scattering BSDF

With rombo.metal and, – we’re introducing a multiple-scattering BSDF to Rombo. The microfaceting theory that is the fundation of the BRDF implementations out there is actually single-scattering. Microfacet models assume that the true physical surface is offset from a geometric surface in the form of a collection of microfacets called microsurface. Microfacet theory is[…]