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Questions tagged [fresnel]

19 questions
6
votes
2 answers

What is a good Javascript RDFa parser implementation?

I am looking to implement a client side RDFa based formatting for a web application. This would be similar to Mark Birbeck's ubiquity-rdfa project. Mark's project looks fantastic but it has at least two drawbacks: It is slow. Adding RDFa…
tremoloqui
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6
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2 answers

Python - OpenDrive Map - Spiral / Clothoid / Euler Spiral / Cornu Spiral Interpolation using Fresnel Integrals

The map format OpenDrive, provides (among others) the geometry of a road. Each segment of the road can have a different geometry (e.g. line, arc, spiral, polynomial). The provided information for a road geometry "spiral", is the following: - s …
Trenera
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6
votes
2 answers

How do you calculate the angle between two normals in glsl?

How do you calculate the angle between two normals in glsl? I am trying to add the fresnel effect to the outer edges of an object (combining that effect with phong shading), and I think that the angle is the only thing I am missing. Fragment…
Levi
5
votes
4 answers

Fresnel diffraction in two steps

I wrote a short matlab script file that is suppose to run Fresnel's propagation (diffraction), such that given a certain input field U0, it will tell you how the field looks after distance z0. I compared the result to textbook results, and it seems…
user1627734
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4
votes
0 answers

Fresnel effect on ray tracing

I have to model the fresnel effect but I think the results are incorrect. I was able to calculate the reflected ray and the transmission ray. My code is written in JavaScript. function shade(objPoint,ray,depth){ color = rgb(0,0,0); shadowRay =…
dreamman
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3
votes
1 answer

How do I combine Phong lighting with Fresnel dielectric reflection/transmission realistically?

UPDATE: I answered my own question about what illumination model to use, but now I need to know how to calculate the Fresnel terms for reflected and transmitted rays. I have a partially-implemented C++ ray tracer. Right now Phong lighting with…
Remy
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2
votes
2 answers

Drawing (Fresnel) ellipse and major axis

I am trying to draw the Fresnel ellipse and a line between two points (x1,y1) and (x2,y2). In addition I am trying to rotate the ellipse using atan2. First, I cannot understand why the drawn red axis is not same with ellipse's imaginative major…
kosar
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2
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1 answer

Three.js: Fresnel Shader - Lights: true issue

I have a small issue with the three.js example fresnel shader. 'lights : true' - if this is 'true' then I get the following error: Uncaught TypeError: Cannot set property 'value' of undefined I'm clueless. Thanks for any suggestions.
SuddenHero
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2
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1 answer

SciPy: What are the arguments in `scipy.special.fresnel(x[, out1, out2])`?

I am trying to plot a clothoid function using SciPy. Here is the syntax for the Fresnel integrals but I cannot understand what are the arguments x, out1, out2 in scipy.special.fresnel(x[, out1, out2])? Formulas in the description are about t and z,…
user1329187
1
vote
1 answer

I am trying to rotate an ellipse with an arbitrary angle in JavaScript. But the outcome is not even an ellipse

I wish to display the Fresnel zone in the chart in which I am hoping to rotate an ellipse by an arbitrary angle. I have given the starting and ending x and y coordinates and I want the ellipse to be rotated not at the center but at the starting…
Priyanka
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0 answers

Refraction in ray tracer produces odd results, how do I combine all color components?

I am writing a ray tracer, so far with only spheres, in C++ and after implementing Phong's reflection model, shadows and reflections, everything seemed to work fine. When I implemented refractions and fresnel I can't seem to get things to look…
Rasmus H
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1
vote
1 answer

How to display RDF data described by Fresnel vocabulary?

I am studying Semantic web while trying to create a simple single page application (SPA). The SPA should be able to display various rdf data (and also allow the user to create new ontologies in a user friendly way). I have full controll of the…
Igor L.
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1
vote
1 answer

Issues implementing Schlick's approximation

So I'm working on creating refracting glass spheres for a ray tracer I am building and am attempting to implement Schlick's approximation for Fresnel refraction as per the suggestion of another user on this site in order to make my glass look more…
user1855952
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0
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0 answers

Distort text behind blob/bubble three JS webgl shader

i have a sphere geometry with shadermaterial consisting perlin noise with fresnel, and vec4 colored fragment, so that it could become transparent. How can i get the text (or basically anything) behind this blob distorted with its perlin noise?
fauxxi
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0
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0 answers

How to implement refraction light in fragment shader?

I am working on an OpenGL ray-tracer, which is capable of loading obj files and ray-trace it. My application loads the obj file with assimp and then sends all of the triangle faces (with the primitive coordinates and te material coefficients as…
Fox1942
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