I''m trying to build a sort of heat effect. I have rendered the scene to a texture, done the proper matrix transformations, but now i need to "disturb" or "warping" the texture so i have the effect of steam (or something like that). I guess that should be done working on texture coordinates. I''ve been looking for examples at nvidia web site, but most examples there are too difficult for my knowledge or require use of extensions (which i prefer not to use). Could you give some hints please ?

I know this has been discussed in the forum previously, search a little...