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1500 questions
4
votes
3 answers
Why use image load / stores instead of FBOs
One example of Image Load / Stores that I have seen could be done using framebuffers instead of Image Load / Stores. Framebuffers have been available longer in OpenGL and so my question is:
Why would you use Images instead of Framebuffers?
What…
Startec
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4
votes
1 answer
About the use of Russian Roulette in Smallpt
I was taking a look at Smallpt (http://www.kevinbeason.com/smallpt), more specifically at the Russian Roulette part. Actually, RR is used in two places along the code: first, to determine ray termination; and second, for the rendering of…
user5681
4
votes
2 answers
How do I include all extensions my system supports using GLAD?
When using the GLAD web service, I am allowed to pick any version of OpenGL and any extensions I want.
If I pick the latest version of OpenGL and "all extensions", will the header file returned by the Web Service #define extensions on my machine…
Startec
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- 19
4
votes
2 answers
How to describe a position of a point w.r.t the position and orientation of 3 other points
Is it possible to describe a position of a point $A$ (in 3D) w.r.t. the position and orientation of 3 other points? If so, how?
FYI, the 3 other points lie on a plane, whereas the point $A$ is not on the plane.
Just to elaborate, initially I have…
Bla...
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4
votes
1 answer
Loading a material via assimp
I'm writing a raytracer and I'm using the assimp library to load objects. I have an object's material specified in a .mtl file:
newmtl rightSphere
Ka 0.01 0.01 0.01
Kd 0.01 0.01 0.01
Ks 0.30 0.30 0.30
Tf 0.10 0.10 0.10
Ns 200
Ni 2.5
illum 7
and I'm…
Michal Kučera
- 353
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4
votes
1 answer
What is better to use for real-time computing Mesh - Plane intersection points, GPU or CPU?
I want to write plugin (library) for Unity3d (it doesn't matter which framework I will choose for this, question is ), for cutting arbitrary mesh with plane (for simplicity it will be plane for beginning).
There are following steps:
1) check every…
Ivan Yakovlev
- 43
- 3
4
votes
1 answer
How are Normal Maps created?
How does one go about taking a single photograph, like a picture of a rock wall, and getting a decent normal map out of it?
If you can, I'd like to learn about the mechanics behind it, and not a piece of software like CrazyBump that does it for me.
Daniel Kareh
- 577
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4
votes
2 answers
Minimum requirements to uniquely represent a 3D object in space
Let's assume we have a 3D object (in 3D space). We get a single representation vertex from this whole 3D object. Given the fact that the object can be moved and rotated in the space in any direction, what are the minimum set of other information to…
angel_30
- 229
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4
votes
0 answers
Algorithm to remove inner faces of a triangulated mesh
I'm trying to figure out the surface area of a mesh that is the result of various CSG union operations between an arbitrary number of other meshes by summing up the same property of each one of it's faces (triangles, in this case) but the result is…
Liordino Neto
- 53
- 5
4
votes
1 answer
How is measured BRDF data recorded?
How is measured BRDF data recorded? Like the MERL BRDF Database.
What kind of equipment is used and what are the key values that need to be recorded?
I know one place this data was used was in the Disney PBR paper.
Arjan Singh
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4
votes
2 answers
Fast approximation of spherical texture coordinates
I'm working on a Software Rasterizer on a sub-30 MHz RISC CPU My current focus is on zooming-in on a slowly rotating planet. For maximum quality, no 3D polygons are involved with the planet - the planet texturing is purely image-based. This is what…
RubyNoob
- 198
- 5
4
votes
1 answer
Worst Case Scenario for Cohen-Sutherland Line Clipping Algorithm
I'm currently enrolled in an entry level Computer Graphics class, and as I'm studying for my final, I realize I have a question regarding the Cohen-Sutherland line clipping algorithm. I understand the basics of the algorithm, such as how to compute…
user3263736
- 41
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4
votes
1 answer
Render with camera perspective off-center
So ordinarily we have this
But I'm after this!
Is it possible to do this? Ideally by changing the projection matrix?
The reasoning is kinda interesting - I am developing for mobile VR, and I have found that putting my phone (and surely many…
Hamish Todd
- 143
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4
votes
2 answers
Why is $pdf(\Psi) = \frac{1}{2\pi}$ when picking from hemisphere uniformly?
I'm trying to figure out why the probability density function for picking a direction uniformly on the hemisphere is $\frac{1}{2\pi}$.
Something tells me this is related to the number of steradians in a hemisphere being $2\pi$, but I can't see how…
PeteUK
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4
votes
2 answers
Strange behaviour in vertex shader with divisions
This is the vertex shader code:
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 myColor;
out vec3 MyColor;
void main()
{
MyColor = myColor;
vec3 v = position;
v.x = v.x/v.z;
v.y = v.y/v.z;
…
Adrian
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