OpenGL Shaders - Rotate a vertex using it's normal

debugcn Published at Dev

Display name

Given the surfaceNormal (gl_NormalMatrix * gl_Normal) and a gl_Vertex how do I rotate the gl_Vertex such that it will adjust to that normal. I want to use this for billboards and general rotation.

2 Questions:

How would you rotate the gl_Vertex using the surfaceNormal (In the .vert shader)?
Should the rotation be done on the GPU (in the shader) or on the CPU? (Please adjust question #1 according to this question given 2 Vector3fs, one for the rotation (normal) the other for the vertex position if it should be done on the CPU)

Thanks!

Aracthor

In most of cases, the rotation should be done on the CPU, by the way of the model matrix (or directly world matrix).

Even if the CPU is slower than the GPU, keep in mind a vertex shader will have been executed for each vertex, whereas a model matrix linked to a mesh, so a lot of vertices, shall be calculated only once per frame if your mesh is dynamic, and only once of your entire program if your mesh won't move.

Collected from the Internet

Please contact [email protected] to delete if infringement.

edited at2021-07-6

Comments

0 comments

From Dev

Related Related

Article

OpenGL Shaders - Rotate a vertex using it's normal

OpenGL Shaders - Rotate a vertex using it's normal

How not to overwrite vertex colors using shaders in OpenGL?

Opengl triangle rotate with vertex modified

How vertex and fragment shaders communicate in OpenGL?

How to set the colour of a vertex in shaders with OpenGL

Using emscripten with opengl shaders

Display voxels using shaders in openGL

iOS using OpenGL shaders in CIKernel

Vertex and Fragment shaders for lighting effect in OpenGL ES20

OpenGL-GLSL drawing 3D GL_LINES vertex shaders vs. vertex

Adding a gradient to a bitmap font using shaders in OpenGL

calculating vertex normal in opengl c++ ( gouraud shading)

calculating vertex normal in opengl c++ ( gouraud shading)

How the Vertex Shaders of OpenGL 4.X process huge number of vertices

Trying to use shaders with Win32 OpenGL but the vertex shader doesn't draw anything

Trying to use shaders with Win32 OpenGL but the vertex shader doesn't draw anything

Calculating a camera's normal in OpenGL?

OpenGL ES Shaders and 64-bit iPhone 5S

How widely supported are Vertex Shaders?

Android opengl es YUV to RGB conversion using shaders

Android opengl es YUV to RGB conversion using shaders

(Modern) OpenGL Different Colored Faces on a Cube - Using Shaders

C# OpenGL - Trying to get the light to move with the camera using shaders

OpenGL: Is there a benefit to using multiple global work groups for compute shaders

webgl rotate a triangle in vertex shader without using transformation matrix

OpenGL: Defining variables in shaders

Shaders in WebGL vs openGL?

OpenGL shaders not drawing a thing :/

.HLSL file for OpenGL Shaders

OpenGL VAO and shaders not rendering