Texture
texture fetch texel value of a texture via normalized coordinates located between$ [0,1] which makes it useful to use with a vec2 uv, or the vec3 position of your raymarch to project it. Result will be interpolated.
texelFetch fetch texel value of a texture via discrete (int) value between $ [textureWidth,textureHeight] . Result won't be interpolated.
Texture
code:texture.glsl
vec3 getTexture(vec2 uv){
vec2 size = textureSize(texSessions,0);
float ratio = size.x/size.y;
return texture(texSessions,uv*vec2(1,-1*ratio)-.5).rgb;
}
...
vec3 col = getTexture(uv);