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opengltexturesglfwtexture-mappingrender-to-texture

How to set texture parameters in OpenGL/GLFW to avoid texture aliasing (wavey behavior on object borders) when viewing objects from a distance?

I am rendering a huge 3D cube array, that sometimes counts thousands of cubes aligned right next to one another. I am rendering a jpg texture to the cubes, which is just a simple color with a black border around the frame.

The problem: The array is huge, and the distant parts of the array get kind of mixed into one another, so to say. In other words, the borders in the distant cubes sometimes completely disappear, sometimes they form an arbitrary wavey line together with other neighboring borders. All in all, the scene looks kind of messy because all the fine details (hard borders between the neighboring cubes) are lost/melted together. After searching for the solution online, I understand that the problem might be in my choice of texture filtering options.

This is how the problem actually looks like in OpenGL: Texture Aliasing between the cube borders 1

Texture Aliasing between the cube borders 2

This is how the current code for loading texture and setting texture parameters looks like:

glGenTextures(1, &texture3);
glBindTexture(GL_TEXTURE_2D, texture3);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

//load image:
data = stbi_load("resources/textures/gray_border.jpg", &width, &height, &nrChannels, 0);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);

By now, I have tried playing with changing different parameters to the function glGenerateMipmap() and altering between the parameters in the glTexParameteri() function, but none did work by now.

Solution

  • If you want to enable Mip Mapping, then you have to use one of the minifying functions like GL_NEAREST_MIPMAP_NEAREST, GL_LINEAR_MIPMAP_NEAREST, GL_NEAREST_MIPMAP_LINEAR or GL_LINEAR_MIPMAP_LINEAR, see glTexParameter and Texture - Mip Maps:

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    A further improvement can be gained by Anisotropic filtering, which is provides by the extension ARB_texture_filter_anisotropic and is a core feature since OpenGL 4.6.

    e.g.

    glTextureParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY, 16);

    See Sampler Object - Anisotropic filtering