Questions tagged [glm]
The glm tag has no usage guidance.
16
questions
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1
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Converting points, vectors, normals between world and object space for a ray tracer gives weird results
I'm writing a ray tracer but having trouble converting rays and normals between world space and object space.
I am creating a Ray, then transforming it with transformation matrices, calculating ...
2
votes
0
answers
160
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What is the projection matrix of reverse (Byzantine) perspective?
I would like to construct a projection matrix for reverse perspective.
I'm using OpenGL and tried to modify concepts from this excelent tutorial.
I came up with:
$$
\begin{bmatrix}
2\frac{(near-M)}{...
4
votes
1
answer
414
views
Three quaternions interpolation with barycentric coordinates
I have three quaternions A, B, C.
I also have a 3D vector P which describes the barycentric coordinate to interpolate.
I want to interpolate the three quaternions with respect to the barycentric ...
0
votes
1
answer
92
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Wrong reflection
Here is a youtube video showing my problem:
youtube.com/watch?v=y8J7VhS2pkM
I think I'm either doing the texture lookup on the reflection texture wrong, or the reflection or view matrix is somehow ...
-1
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2
answers
767
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How can i wrap the earth image around a 3D Sphere using OpenGL, GLFW, GLAD, GLM?
Please help me out with this thing and currently i am a little more than a beginner so please tell me in that context. i don't need any obsolete methods for creating this like using GLUT or GLEW.can ...
0
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0
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790
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How to rotate an object in OpenGL on the X, Y and Z axis on its local coordinates?
I've read multiple tutorials, but I still can't understand how do I properly rotate an object in 3D space on all 3 axis at once. For example, I'd like to give the object a pitch of 60 degrees, yaw of ...
-1
votes
1
answer
2k
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Difficulty including GLM into Visual Studio with OpenGL
I have been trying to implement GLM (math library) into Visual Studio with OpenGL. I have followed and watched many online resources that point me to include only the GLM folder inside the ...
1
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0
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1k
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360 degrees rotation around x axis
How do we rotate the camera around x axis 360 degrees, without having to flip the axis, meaning without having the strange flip after we go over +-90 degrees on <...
1
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1
answer
237
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My (ADS) shader doesn't render the light direction correctly
This is what I'm doing:
vertex shader:
...
1
vote
1
answer
513
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Am I passing the correct matrices for my shader? openGL/C++
On page 89 of David Wolff - OpenGL 4.0 Shading Language Cookbook book, it suggests a way to set up up a Phong shader in the fragment stage. It lists some different matrices to pass via uniform, and I ...
2
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0
answers
167
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With OpenGL, is it correct to apply model transformation to rotate the camera?
Having taken a basic CG course, I remember that transformations are relative, so rotating the camera is identical to rotating the view in the opposite direction. Right now I want to implement camera ...
4
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1
answer
8k
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understanding glm::perspective vs glm::ortho
I'm new to computer graphics. I played around with OpenGL and now am trying out Vulkan.
Basically what I want to do, in 2D is have an 800x800 window, and I want that to represent 800 meters by 800 ...
11
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4
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13k
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Multiple viewports with modern OpenGL?
I use SDL2.
Currently my only shader has a MVP matrix, and transforms the points with it.
I calculate my View and Projection matrix for a camera with GLM:
...
3
votes
1
answer
6k
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Screen to World coordinates glm::unProject
I'm having some trouble trying to figure out how to go from a coordinate on the screen, to 3D world coordinates on a plane.
My case is as seen on the picture further down. World origin is in the ...
3
votes
1
answer
709
views
Ray-tracing the Cornell Box results in really inconsistent image
So I have a vector of glm::vec3 containing the triangles for the classic Cornell Box called triangles. The Draw method casts a ray for each pixel on the screen and ...
24
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1
answer
24k
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Get vector length with GLM
I am quite confused over how GLM library is behaving or I am using it improperly.
glm::vec2 testVec(6,-4);
float len = testVec.length();
I get the value ...