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Questions tagged [specular]

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2 votes
1 answer
1k views

PBR and Specular Aliasing

I have been following LearnOpenGL.com's tutorials on PBR. Everything makes sense and I wrote up a shader for my physically based renderer. I noticed that the results look great, however all of my ...
Brady Jessup's user avatar
5 votes
1 answer
2k views

Phong and the Rendering Equation: What's with the cosine?

Ignoring emission and shadowing for simplicity, the rendering equation can be stripped down to: $$L(x, \, \vec \omega) = \int_{\Omega}{f_r(x, \, \vec \omega^\prime, \, \vec \omega) \, (\vec \omega^\...
David Kuri's user avatar
  • 2,293
1 vote
1 answer
529 views

Direct illumination, specular surfaces, and MIS

Multiple Importance Sampling (MIS) is a technique used by Veach's VCM technique to balance responses of different surfaces to different types of importance sampling for direct illumination. My ...
Paul Ferris's user avatar
1 vote
3 answers
396 views

Same specular lighting on both tris in a quad (for "low-poly" "flat shading" look)?

Here's an example of the flat shaded squares I want. But my squares are made of two triangles, and I'm getting flat shading of those triangles. In openGLES 3.1 (android), I'm turning off ...
hyperpallium's user avatar
2 votes
0 answers
484 views

How to simulate specular reflection in Light Tracing?

I am implementing light tracing from this website. The right wall on the below image is perfect mirror(specular reflection). Its BRDF returns zero that's why it's been rendered black. But how is it ...
ali's user avatar
  • 740
10 votes
4 answers
28k views

What is the difference between glossy and specular reflection?

What is the difference between glossy and specular reflection? What is their relations with BRDF?
chaosink's user avatar
  • 591
3 votes
0 answers
565 views

Problem with specular BRDF (Monte Carlo & Path Tracing)

Above on the left is my attempt and on the right is what I'm aiming for.As you can see my sphere with the specular brdf has a weird dark ring In my radiance function I am recursing through the ...
Aloof's user avatar
  • 31
1 vote
0 answers
211 views

Pathtracing specular reflections vs. specular highlights

In path-tracing, is a specular reflection model like Blinn-Phong useful? Is it more accurate to render a complete reflection dependent on the objects roughness?
Orange Mushroom's user avatar
3 votes
2 answers
2k views

Phong: Real-time rendering of Metal and Plastic Materials

Using a shader that works like Phong, what would be the difference between painted Metal and plastic? I seem to remember reading in books years ago, that I no longer have access to, the following: ...
Invariant's user avatar
  • 133
3 votes
1 answer
370 views

How to send shadow rays to window light source with glazing

For rendering an indoor scene where light source is skylight coming in through the window opening, one can consider the window polyline as the light source, with the sky distribution, in direct ...
ali's user avatar
  • 740
5 votes
1 answer
1k views

Fresnel and specular colour

I'm trying to implement Cook-Torrance BRDF and had previously bookmarked this question as it looked very well thought out. Going through it, I'm confused about the Fresnel equation. The author has the ...
PeteUK's user avatar
  • 700
1 vote
1 answer
265 views

Specular exponent spectrum

I read the MTL specification for materials and noticed that the specular exponent Ns must be a scalar value instead of a spectrum. Would a specular exponent with three color channels (i.e. RGB, XYZ, .....
Matthias's user avatar
  • 1,084
4 votes
1 answer
1k views

How to handle specular highlights with reflection / total internal reflection in a ray tracer?

Let's say that I have a raytracer that is rendering a scene that includes a refractive object. When a ray hits the refractive object, I know that I can use the fresnel equation (Schlick's ...
Alan Wolfe's user avatar
  • 7,801
31 votes
2 answers
7k views

Path tracing the Cook-Torrance BRDF

-- Sorry for the long post, but I prefer to do that way because "Devil is in the details." :) I am writing a path tracer from the scratch and it is working nicely for perfectly diffuse (Lambertian) ...
user avatar
4 votes
1 answer
728 views

Normal vector in Phong Illumination Model should be normalized?

I'm studying Illumination subject these days and I was given a problem which asks to calculate the intensity using phong illumination model. I'm little bit confused whether I should calculate normal ...
Samitha Nanayakkara's user avatar

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