I've been trying for a couple hours now to try and get some advanced shader mods, and actually to be specific, OptiFine, ShadersMod, and SEUS v10, to work on Tekkit. I've seen a fuckload of tutorials on how to get it to work with Tekkit Lite, and they all are like bam copied into the modpack.jar file.
I try it and after I log into the launcher, minecraft launches but only whitescreens. No Mojang screen at all.
Any help would be greatly appreciated, thank you.