   bilinear interpolation doesn't work with GL_FLOAT?
  Hello,can it be that bilinear interpolation doesn't work if i define a texture, that holds GL_FLOAT values? I defined it like this:glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_LUMINANCE, GL_FLOAT, buffer);Now I am accessing this texture in a fragment shader and very obviously, there is no interpolation performed. Is it really a problem because of the GL_FLOAT or does the fragment shader ignore that I wanted a linear interpolation?I am a little confused O.o   
  I'm getting the same effect using a GL_FLOAT texture as a specularity map. I know that GL_FLOAT textures don't have blending functionality until nv4, but I am running a 7200GT and still don't get interpolation. Although more precisely it looks like partial interpolation. I will post a screen shot in 45 minutes or so (when I am at home). Do you have a screenie you can upload?;  Yes, give me some minutes and I'll upload a screeshot of what happens here. I am using the GL_FLOAT texture to hold a lighting distribution of a car headlamp.   ;  ok here is the pic of what i got. thes "jumps" in the color should not appear if the interpolation was working :-/http://datahaven.de.vu/;  This is what my problem looks like (I've tried to draw boxes around the texels to show what size they are, as you can see there is some interpolation but it is aliased) ;  I'm planing on switching to a 256 greyscale specularity map. I would recommend the same for you until we work out what the problem is, or someone else enlightens us.   ;  I found out what the problem was with my texture. Actually I had interpolation working, but I was saving very small floats in the texture while converting it to OpenGL via glTexImage2D, they lost their precision. Therefore I really had areas with exactly the same values written :-( I am afraid OpenGL saves even GL_FLOATS just 8 bit :-( I partially solved the problem, by exchangingglTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_LUMINANCE, GL_FLOAT, buffer);byglTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, width, height, 0, GL_LUMINANCE, GL_FLOAT, buffer);now I can save real 32 bit floats in my texture (and I am also not limited to a range from 0.0 - 1.0 when I acces the color values within the shader) but now the graphic card can really not perform interpolation on 32 bit floats anymore :-( Even though it looks better now, because I am using a 2048 x 2048 texture, which after my calculation only creates quite small fragments. Anyway, would be much better to have 32Floats and interpolation working. (so if anyone has ideas on that!?!?)I don't know if this solution helps with your problem? I am afraid your case is quite different :-/   ;Quote:Original post by rapunzelI am afraid OpenGL saves even GL_FLOATS just 8 bit :-( I partially solved the problem, by exchangingglTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_LUMINANCE, GL_FLOAT, buffer);Of course, your GL_RGB argument is the texture internal format (ie. the format used to store the texture in the graphics card). GL_RGB is fixed point, 8 bits per component. The GL_FLOAT before-last argument is the format of your own data (buffer). OpenGL was converting your float data to 8 bits. It's the correct behavior according to GL's specification, so there's nothing weird going on here.Y.   