![]() ![]() Specular reflection becomes less focussed as light is scattered on a surface that tends toward diffuse reflection. There is a continuum of reflective surface types from a perfect mirror (where specular reflection occurs) tending towards diffusion surfaces and absorbing surfaces. The degree to which light is reflected from any surface depends on how mirror-like it is. Imperfectly reflect light: The surface is an imperfect mirror and some of the light is scattered.įor the photographer, the way light behaves when it hits a surface is important.Absorb light: the light is absorbed (the energy of the light is taken up by the material).In real-life, non-perfect situations, the base material of the mirror and the surface of the mirror may: So yes, we would like to archieve a similar result to the double-ball-maxwell-trick within a single shader, even through the existing disney shader if that doesn't change the nature of the shader itself.In a perfect reflection all the light will be reflected from the mirror surface. This reflection problem, which requires a completely different description of the material depending on the overall brightness of the material, makes things slightly more complicated. Our rendering system tries to offer its customers an extremely simple material model however, to achieve this with less effort, we would ideally need a rendering engine that behaves linearly. ![]() The good thing is that LuxCore is open so we can help to find a solution to this problem. In fact it was one of the biggest problems for us with Maxwell and now with LuxCore. I knew about this reflection problem in Maxwell, but I hoped that LuxCore had solved it Unfortunately that's not the case. Our rendering platform, Felix, currently uses Maxwell but we want to migrate everything to LuxCore. To be honest, we're doing these photo tests to have a solid base on which to align multiple rendering engines from a quality standpoint. For what i know the sepecular reflection is always stronger at the tangent as on the perpendicular, and never the opposite, correct? That could mean that the reflection with the lowest roughness always dominates the tangent.Sorry, may i say silly things, unfortunately I'm technically very ignorant, that's why sometimes i stick to the empirical approach I don't think, by the way, that the disney shader offers much more to discover and i also don't believe that the white halo is the result of an esthetic choice by disney because adding such a kind of halo has never been a problem in any rendering engine since 1995.īy examining the result i got in Maxwell, using the double sphere trick, which just replicates reality, even the math behind that results do not seems the most complex of this world to me it seems a simple fresnel used to weight two (or more) different types of reflection, diffuse vs specular. Not even mentioning the fact that if in this moment an artists wants to deliver a 3D representation avoiding this kind artifact hi will not succeed using luxcore. I think this feature i very important for a rendering engine which states to put physical correctness at top of his priorities.īut forgetting luxcores official goals i'm sure that this features would give luxcore the final touch regarding naturalism and image smoothness. Right now, you are asking "Why does a model that was fitted to some materials not work well on another material?" Your first question should be " Which model best represents the material that we use?". You are working with a real experimental setup and comparing it to a computer model. From what I read I have the impression that this whole "bright rim on the edge of an object" was a primary motivation for the Disney shader. ![]() Moreover, they pretty much explicitly discard a Lambertian diffuse model, which would be represented by the standard Matte matieral, and should be a good model for real matte paints. The bright ring simialrly appears in Figure 8 in the Hanrahan-Krueger model, which is also mentioned in section 5.3 regarding implementation details. In your scene, you observe the sphere from the front with the light overhead. Now, I'm not quite through the paper yet, but in the first section they discuss certain specular microfacet (including grazing retroreflection) as well as diffuse reflectance models. Because of this, our philosophy has been to develop a \principled" model rather than a strictly physical one. In developing our new physically based reflectance model, we were cautioned by artists that we need our shading model to be art directable and not necessarily physically correct. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |