A vector of 3 floats.
vec3
// vec3(float x, float y, float z)
vec3 a = vec3(1, 2, 3) // constant - uses the vector block
float y = 10
vec3 b = vec3(5, y, 5) // uses the make vector block
const float x = 8
vec3 c = vec3(x, 3, 5) // constant - uses the vector block