This Metallic Paint uber shader is a powerful three layers material able to simulate the complete light transport that happens within the layers. The flakes which are in the middle layer, are multi-scale and BRDF-based (not pattern based) so that at distance they converge to a smooth reflection while at close views they act like[…]
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[…]
This node basically does multiple scattering refractions. When with romboRefract (or Standard Material) we do engage Scatter in the Refract (transmission) rollout we are doing instead volumetric single scattering. Multiple scattering is slower but more expressive. We can’t really render a resin statuette like this one below with single scattering. Let’s see its main parameters[…]
The SSS Random Walk node is a state-of-the-art subsurface scattering shader. We employ a new sampling strategy for random walks that takes all previouses approaches and put them together for a more effective sampling with reduced render times and great solution quality. Basically what lately did put pathtraced SSS into production is the understanding that[…]
The SSS Dipole shader implements all the relevant dipole models for subsurface scattering available in computer graphics.. namely Standard, Better and Directional dipoles. They are of particular interest because they are better (at matching real life reference materials) than diffusion SSS and way faster than raytraced (random walk) SSS. Let’s see its GUI and main[…]
Microfacet-based normal mapping is an alternative way of faking geometric details without corrupting Monte Carlo based path tracing light transport and it’s available in ReflectMultiScatter and ReflectGeneralized. Theoretically it is well-defined, symmetric and fully energy conserving. On the other side it means that classic normal mapping has none of the properties above resulting in a[…]
Reflection hazying is actually an artifact. It happens due to micro imperfections which widen the actual reflection lobe making reflections appear less vivid and radiant, more milky and less contrasted. Hazing generally is due to poor industrial processes so that metals and other reflective surfaces have an inferior finish quality because of bad drying or[…]
This reflection node is a powerfull shader that supports both geometrical optics and wave optics glints, flakes, brushed patterns and scratches. Unlike in geometric optics, the contributions from different parts of the surface can sum non-linearly due to interference effects, to create the characteristic diffraction effects of wave optics.. ie. those colored patterns we see[…]
The yarn-based material has been updated with: sheen and reflection lobes build-in patterns with HSV controls an all new phase function for better controllable fiber scattering a roughness patch size to better control fiber roughness and specular pattern variations an indirect glossy versus indirect diffuse parameter to better approach some kind of textiles better overall[…]
With rombo Reflect shaders, – we’re introducing microfacet multiple-scattering in two forms: approximated and true random walk multiple scattering. The true multiple scattering is available only with the ReflectMultipleScatter node while the approximated stuff comes with any specular additional lobe attached to the Diffuse nodes; it is an option with the MultipleScatter node itself and[…]
So in the while also Autodesk has added an Adaptive Sampler to the Arnold renderer. It is very different from the one we first demo’ed here last year. The now build-in Arnold adaptive sampler is image based while ours is a multi-dimensional adaptive sampler. What’s the main difference ? A very simple and yet very[…]
While Arnold already uses a stochastic approach for transparency, it comes only as a ‘closure’. Which means that for custom shaders that do not use an all closure approach it is not available, so we had to add one ourselves. Stochastic transparency makes a huge impact on render times where bounces depth is high. Top[…]