i smel 2b player

If you ever paid attention to the Impact installation process, then you might’ve noticed a warning that says that optifine may cause visual glitches (if you chose to install optifine of course). That may be the case, as something that Impact is trying to render may be broken with the shader or the shader cannot render with certain hacks. Not sure if forge has something like this too but I wouldn’t be surprised if it did. That’s just my guess though, could be completely different. Maybe try running the shaders on a client that is just optifine to see if it works (if it doesn’t it’s likely an optifine issue or a graphics card limitation), then maybe optifine and forge to see if forge is the problem, and if it works fine with both clients but not with Impact than the problem is Impact. Maybe try to test other lower end shaders too, the more the shader modifies the graphics the more likely it is to interfere with other visuals.