GL_LINEAR_MIPMAP_LINEAR & GL_LINEAR

[devdept]

Hi All,

Is it normal that I can't get the texture quality GL_LINEAR with GL_LINEAR_MIPMAP_LINEAR when zooming very close to the textured rectangle?

Why if I use MIPMAPS I get less quality (zooming very close to the model) when the first - bigger - MIPMAP is the same image I use with GL_LINEAR and without MIPMAPS?

Is GL_LINEAR the only best texture quality option when looking very close to the model?


Thanks,

Alberto

[Bob]

I'm not sure I understand what you're comparing here. Comparing GL_LINEAR and GL_LINEAR_MIPMAP_LINEAR when zooming a texture, if that's what you're doing, makes no sense, as the latter isn't even a valid magnification filter.

[Relic]

Or to put it another way, when zooming in to a textured object which is NOT requiring the texture to be magnified, you will use the minification filter and in the linear_mipmap_linear case that will interpolate between prefiltered images which might not look as crisp as the full resolution level of detail 0 texture you're using when the filter is linear only. If that's what you meant, yes, this is to be expected. Though mipmapping will show less texture aliasing in that case. You might see that when animating the object.

Mipmap visuals depend on the quality of the prefiltered mipmap images. Standard are simple 2x2 box filters recursively applied to higher level of detail texture, which are ugly. There exist better filters.