This is my first question here, i am using opengl es 2.0 and am currently working with a custom shader. My problem is that when i try to use the vertex normal attribute it shows nothing. I know that the normals are set correctly and the shader is seeing the normal because i can add it to position in the vertex shader and all faces will explode outward by 1.0. however if i do anything with it in anyway it simple shows nothing on screen.
below is the code for this i have commented out the parts to allow it to work. if i uncomment the normal part it simple doesn’t show anything with no compile errors.
uniform mediump mat4 ModelViewMatrix;
uniform mediump mat4 ProjectionMatrix;
uniform mediump mat3 NormalMatrix;
uniform mediump vec3 LightPosition;
attribute mediump vec3 VertexPosition;
attribute lowp vec3 VertexNormal;
varying lowp vec3 LightColor;
mediump vec3 position = vec3(ModelViewMatrix * vec4(VertexPosition, 1.0));
//lowp vec3 normal = normalize(NormalMatrix * VertexNormal);
/* Calculate the light direction */ mediump vec3 lightdirection = normalize(LightPosition - position); /* Calculate the intensity of the light with the dot product */
//lowp float ndotl = max(dot(normal, lightdirection), 0.0);
/* Light color = intensity * color of the light */ LightColor = vec3(1.0); /* Transform the positions from eye coordinates to clip coordinates */ gl_Position = ProjectionMatrix * vec4(position, 1.0);