Hi, I have a 2D sprite with normal map and I use the following fragment shader to give it a 3D effect:
uniform texture normal;
//normal maps expect Y-up, but 2D is Y-down, so must mirror this.
NORMAL = tex(normal,UV).rgb * vec3(2.0,-2.0,1.0) - vec3(1.0,-1.0,0.0);
The problem is that the effect is almost invisible if the energy of the light is low. But if I set it to high, the lightning of the background does not look good.
How can I increase the energy in the shader itself?