Perspective camera/Vertex Shader/Fragment Shader

PerspectiveCamera

****************************************************
********PERSPECTIVE CAMERA**************************
****************************************************

private void Render ()
		{
			if (!loaded)
				return;
			GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);

			#region CAMERA
			//***************** CAMERA
			//************************
			if (CameraMode == "Perspective")
			{
				updateCameraTextBoxes();

				//GL.UseProgram(colorProgram.id); //WHEN I ENABLE THIS LINE THE MODEL DISAPPEAR FROM THE SCEEN

				// Use cooresponding shader when setting uniforms/drawing objects
				int lightPosLoc = GL.GetUniformLocation(colorProgram.id, "light.position");
				int viewPosLoc = GL.GetUniformLocation(colorProgram.id, "viewPos");

				GL.Uniform3(lightPosLoc, lightPos.X, lightPos.Y, lightPos.Z);
				GL.Uniform3(viewPosLoc, CameraWalkThrough_StartPos.X, CameraWalkThrough_StartPos.Y, CameraWalkThrough_StartPos.Z);
				// Set lights properties
				GL.Uniform3(GL.GetUniformLocation(colorProgram.id, "light.ambient"), ref lightAmbient);
				GL.Uniform3(GL.GetUniformLocation(colorProgram.id, "light.diffuse"), ref lightDiffuse);
				GL.Uniform3(GL.GetUniformLocation(colorProgram.id, "light.specular"), ref lightSpecular);
				GL.Uniform1(GL.GetUniformLocation(colorProgram.id, "light.constant"), lightConstant);
				GL.Uniform1(GL.GetUniformLocation(colorProgram.id, "light.linear"), lightLinear);
				GL.Uniform1(GL.GetUniformLocation(colorProgram.id, "light.quadratic"), lightQuadratic);

				Matrix4 projection = Matrix4.CreatePerspectiveFieldOfView(fov * degToRad, (float)glControl1.Width / (float)glControl1.Height, nearCuttingPlane, farCuttingPlane);
				Matrix4 view = CameraLookAt.GetViewMatrix_OrbitSelected(CameraMode, targetDistance);
				ViewProjectionMatrix = view * projection;

        			// Transformation matrices
				GL.ProgramUniformMatrix4(GL.GetUniformLocation(colorProgram.id, "projection"), 1, false, ref projection);
				GL.ProgramUniformMatrix4(GL.GetUniformLocation(colorProgram.id, "view"), 1, false, ref view);

				// Draw the loaded model
				Matrix4 model =  new Matrix4 (new Vector4 (1,0,0,0), new Vector4(0, 1, 0, 0), new Vector4(0, 0, 1, 0), new Vector4(0, 0, 0, 1));
				GL.ProgramUniformMatrix4(GL.GetUniformLocation(colorProgram.id, "model"), 1, false, ref model);

				ourModel.Draw(colorProgram.id); //HERE I DRAW THE MODEL, BUT IF I ENABLE THE COMMAND LINE GL.UseProgram(colorProgram.id) THE MODEL DISAPPEAR FROM THE SCEEN!!!
        
			}
      
			GL.MatrixMode(MatrixMode.Projection);
			GL.LoadIdentity();

			GL.LoadMatrix(ref ViewProjectionMatrix);
			#endregion

			statistics();

			Grid.Render_XY(Grid_xSpacing, Grid_ySpacing, Grid_size, Grid_drawGrid_XY);
			Grid.Render_XZ(Grid_xSpacing, Grid_zSpacing, Grid_size, Grid_drawGrid_XZ);

			draw_Geometries();

			drawGeometries_Style();

			glControl1.SwapBuffers();
		}
		
		
		
****************************************************
********VERTEX SHADER*******************************
****************************************************
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec3 normal;
layout (location = 2) in vec2 texCoords;

out vec3 Normal;
out vec3 FragPos;
out vec2 TexCoords;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
    gl_Position = projection * view * model * vec4(position, 1.0f);
    FragPos = vec3(model * vec4(position, 1.0f));
    Normal = mat3(transpose(inverse(model))) * normal;  
    TexCoords = texCoords;
} 


****************************************************
********FRAGMENT SHADER*****************************
****************************************************
#version 330 core
struct Material {
    sampler2D diffuse;
    sampler2D specular;
    float     shininess;
};  

struct Light {
    vec3 position;  
  
    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
	
    float constant;
    float linear;
    float quadratic;
};

in vec3 FragPos;  
in vec3 Normal;  
in vec2 TexCoords;
  
out vec4 color;
  
uniform vec3 viewPos;
uniform Material material;
uniform Light light;

uniform sampler2D texture_diffuse1;


void main()
{
    // Ambient
    vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
  	
    // Diffuse 
    vec3 norm = normalize(Normal);
    vec3 lightDir = normalize(light.position - FragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));  
    
    // Specular
    vec3 viewDir = normalize(viewPos - FragPos);
    vec3 reflectDir = reflect(-lightDir, norm);  
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
    vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
    
    // Attenuation
    float distance    = length(light.position - FragPos);
    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    

    ambient  *= attenuation;  
    diffuse  *= attenuation;
    specular *= attenuation;   
       
	//color = vec4(1000.0f + ambient + diffuse + specular, 1.0f);
	color += vec4(texture(texture_diffuse1, TexCoords)) ;
}