#version 410 core

layout(location = 0) in vec3 vertexPosition;
layout(location = 1) in vec2 vertexTexCoord;
layout(location = 2) in vec3 vertexNormal;

uniform mat4 modelViewProjectionMatrix;
uniform mat4 modelMatrix;

uniform vec3 cameraPos;

out vec3 interpNormal;
out vec2 interpTexCoord;

out float visibility;
const float density = 0.006;
const float gradient = 2.0;

void main()
{
	gl_Position = modelViewProjectionMatrix * vec4(vertexPosition, 1.0);
	interpNormal = (modelMatrix * vec4(vertexNormal, 0.0)).xyz;
	interpTexCoord = vertexTexCoord;

	float distance = length(gl_Position);
	visibility = exp(-pow((distance*density),gradient));
	visibility = clamp(visibility,0.0,1.0);

}