   Discontinuity when doing linear filtering with a shader
  Hi everyone, it's been a while :)This is the situation: we implemented a linear filter using a 3x3 matrix (the kernel) which makes a weighted average of the current pixel and its adjacent ones.However, since we do this on very large images, we had to render them using many textured quads. We set the quads' position manually (i.e. in their vertex buffer). We believe this is the cause of our problem: In the boundaries between quads, discontinuities appear.Right now, we are using an Effect and a pixel shader which has many functions, so we do everything in one pass. We are considering using a vertex shader for positioning the textures, but we are not very sure how to go about this. Our top priority is eliminating the discontinuities. Any suggestions?   
  Duplicate edge pixels between texture tiles, or run another version of the shader along the boundary edges that takes the texture on either side of the edge   ;  Alright, I'm gonna try duplicating the edge pixels. By the way, I'all also have to redefine the zoom filters (min, mag and mip filter, I believe) in my Effect file so as to avoid discontinuities caused by the default implementation. Just wanted to add that   