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CFP: ZhejiangLab Cup Global Artificial Intelligence Competition 2018

ZhejiangLab Global Artificial Intelligence Competition is held by Zhejiang Lab, Zhejiang Expert Committee on Artificial Intelligence Development (AI top 30), China Artificial Intelligence Industry ...
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2answers
98 views

ScratchAPixel : Understanding how to use Perlin's permutations hash table

Consider this course : https://www.scratchapixel.com/lessons/procedural-generation-virtual-worlds/procedural-patterns-noise-part-1/creating-simple-2D-noise . In sub-part Introducing the Concept of ...
2
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0answers
52 views

Using GPU instead of CPU in Scala

I wrote a program that displays points expressed in 3D in a 2D canvas, using perspective projection. The aim is to display a cube. Each face of the cube is drawn by linearly interpolating the points ...
3
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1answer
107 views

How to deal with light leaks?

I'm struggling with light leaking through meshes (especially thin ones) due to interpolation between probes located on the opposite sides of those. First approach I took was mapping all static ...
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0answers
50 views

Perspective correct interpolation

I am writing a software renderer and I want to know if my interpolation is perspective correct or not. Here's what I am doing : I divide the vertices by w coordinate : ...
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2answers
382 views

Geometric interpretation of this bilinear interpolation equation?

Bilinear interpolation can be achieved by interpolating two values across the x axis, and then interpolating between the results across the y axis, like in the image below (from https://blog.demofox....
4
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1answer
85 views

How to obtain generalized barycentric coordinates for n-sided polygon?

Quadrilateral linear basis functions(generalized barycentric coordinates) are defined as: What are the steps to calculate the above functions? Is it possible to obtain basis functions for a 5 sided ...
4
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0answers
106 views

Sinc interpolation and Ideal reconstruction example

I am trying to apply sinc interpolation on this data set. The patches in the left image is a snapshot of AutoCAD 3d faces. Lux values are calculated for centre of each patch that are in 0.3m x 0.3m ...
5
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1answer
189 views

The mathematics of two dimensional interpolation on a quad

I am trying to wrap my head around how exactly the GPU interpolates texture coords on a quad. I realize to the GPU a quad is two triangles but I find thinking in terms of the whole quad to be easiest. ...
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1answer
152 views

Bilinear Interpolation

I am trying to implement bilinear interpolation as described in the paper Spatial Tranformer Networks by Jaderberg et. al (see link to paper). They describe bilinear interpolation in Equation 5 as: $$...
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0answers
51 views

General interpolation practices

Say my animation scenario contains one mesh interpolating into another (possibly approximating over other meshes), using Bezier curves. I know that for smooth surfaces, where normals can be ...
2
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0answers
44 views

Interpolating normals during animation

I'm doing linear tweening of a cyllinder to a cone of equal radius and height in OpenGL. I know parametric equations of both of them, so I derived vertex normals accordingly. Now, I know, that proper ...
11
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1answer
872 views

How are mipmap levels computed in Metal?

My question is specifically in regards to Metal, since I don't know if the answer would change for another API. What I believe I understand so far is this: A mipmapped texture has precomputed "...
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vote
1answer
207 views

Perlin Noise with Smooth function vs Lerp

I tried implementing Perlin Noise using the Wikipedia as my main resource. From what I can tell my implementation of the ...
2
votes
1answer
124 views

What is a common approach to smooth structures in textures?

I have a screen-aligned texture resulting from multiple rendering passes. It looks about this: I want the edges to appear smoother than they do now (but still keep their characteristic shape). When ...
2
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0answers
29 views

Make 3d objects from 3 projections in 3D Studio Max

In the early 3D Studio days before it got Max in its name it was possible to make a 3d object by defining its projections in xy, xz and yz plane. 3ds would then interpolate a 3d object from the ...
6
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1answer
571 views

Normal Interpolation for Phong shading

As the title says I have been trying to understand the normal interpolation for the Phong shading/lighting model. I am unsure of the equation to calculate the normal but I have come across this ...
3
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1answer
140 views

How to use Monotone cubic interpolation in 3D?

I wanted to use Monotone cubic interpolation, but the site only provide explanation for 2D case. How can I extend it to 3D?
6
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2answers
1k views

How do I use barycentric coordinates to interpolate vertex normal?

Given a triangle and a point inside the triangle in Cartesian coordinate system, I compute the Barycentric coordinate of the point like this: ...
5
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1answer
378 views

Screen coordinates, barycentric coordinates and global coordinateas

To continue with this my other question, here's the problem. So, I've a slide, which I'm trying to understand. Here are my questions. What are the barycentric coordinates of? From my previous ...
6
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1answer
170 views

How to rasterize a line when the background color is not always white?

I've to rasterize a line taking into account not only the background color of the screen, which is white, but also the color of other objects in the scene. In my case, I've just another object, a ...
4
votes
3answers
60 views

Does the blending matrix change between calculating various curve segments in a uniform cubic B-splines approximation?

I would like to ask about uniform (periodic) cubic B-splines (approximation, no interpolation). $$B=1/6\begin{bmatrix}-1&3&-3&1\\3&-6&3&0\\-3&0&3&0\\1&4&1&...
4
votes
1answer
249 views

Creating a gently moving 2D fog effect

I am trying to create a fog-like effect, similar to that found using perlin noise. I know where I can find information about that effect, but it's harder for me to tell if it's an efficient route for ...
6
votes
1answer
265 views

Image rescaling algorithm

Suppose I have to use bilinear interpolation to rescale image. I more or less understand how enlargement works in case of integer scale factor. But what to do with non-integer scale and especially ...
3
votes
1answer
215 views

Find closest point on surface interpolated by 2d matrix of points

I have rectangular matrix of 3d points sampled from a parametric surface. In my program this matrix provides base points for bilinear interpolation of surface (In any (u,v) point it returns 3d point ...
5
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1answer
137 views

How can you interpolate over an array of say 5 colors?

I have an array of color values. I have an interpolating parameter, t, which varies from 0 to ...
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0answers
172 views

How to do keyframe interpolation on matlab?

I want to do keyframe interpolation in matlab. If I understand correctly, it uses splines to approximate the the motion of specific pixel points within the frames(through transforms). Correct me if I'...
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2answers
1k views

What is bilateral upsampling?

I've worked with various interpolation algorithms including linear, cubic (and bilinear and bicubic), other bezier (and nurbs, etc) based interpolations, lagrange interpolation and some others, but I ...
7
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1answer
251 views

Perspective correct interpolation of normal values

I'm currently writing a software rasterizer and I'm at the point where I can draw arbitrary triangles with vertex colors and perspective correct texture mapping. I do point and directional lighting by ...
5
votes
1answer
695 views

Is there a way to interpolate color across the line with only integer calculation ?`

Here is my function that does interpolation ...
4
votes
2answers
500 views

Linear interpolation on Plane (Marching Cubes)

Let's assume I have the following cube. Let's assume the isovalue = 0. I would like to draw the resulting triangles of the isosurface. I know that first I define which values are inside or outside ...
4
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0answers
555 views

Which interpolation algorithm does MS Paint on Windows 7 use for image rescaling?

I was about to scale this image down to 64x64 pixels: The result I got on MS Paint on Windows 7 was surprisingly good (i.e. crisp edges): , whereas scaling it with GIMP resulted in for cubic and ...
5
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1answer
471 views

Interpolating vectors on a grid

If you have values on a grid and you want to find the value of a point within one of the cells, you can use techniques like bilinear or bicubic interpolation to get the data at that point. What ...
4
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0answers
54 views

MRF and Textures

I am pursuing my research in Texture Interpolation. After digging deep into it, I'm stuck at a point. It is proven that textures can be modeled as Markov Random Fields and that each texture can be ...
11
votes
1answer
352 views

Is a cubic Lagrange interpolation tensor product the same as bicubic interpolation?

I just implemented some interpolated texture sampling by sampling the 4x4 nearest pixels then doing Lagrange interpolation across the x axis to get four values to use Lagrange interpolation on across ...