- normalmaps.png (144.57 KiB) Viewed 1508 times
Adding the shader code below.
VSH:
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// Incoming per-vertex attribute values
attribute vec4 vVertex;
attribute vec2 vTexture;
attribute vec3 vNormal;
uniform mat4 mvpMatrix;
uniform mat4 mvMatrix;
uniform mat3 normalMatrix;
uniform vec3 vLightPosition;
// Outgoing normal and light direction to fragment shader
varying vec3 vVaryingNormal;
varying vec3 vVaryingLightDir;
varying vec2 vTexCoords;
void main(void)
{
// Get surface normal in eye coordinates and pass them through to the fragment shader
vVaryingNormal = vNormal;
// Get vertex position in eye coordinates
vec4 vPosition4 = mvMatrix * vVertex;
vec3 vPosition3 = vPosition4.xyz / vPosition4.w;
// Get vector to light source
vVaryingLightDir = normalize(vLightPosition - vPosition3);
// Pass the texture coordinates through the vertex shader so they get smoothly interpolated
vTexCoords = vTexture.st;
// Transform the geometry through the modelview-projection matrix
gl_Position = mvpMatrix * vVertex;
}
FSH:
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// Uniforms
uniform lowp vec4 ambientColour;
uniform lowp vec4 diffuseColour;
uniform lowp vec4 specularColour;
uniform sampler2D colourMap; // This is the original texture
uniform sampler2D normalMap; // This is the normal-mapped version of our texture
// Input from our vertex shader
varying lowp vec3 vVaryingNormal;
varying lowp vec3 vVaryingLightDir;
varying highp vec2 vTexCoords;
void main(void)
{
lowp float maxVariance = 10.0; // Mess around with this value to increase/decrease normal perturbation
lowp float minVariance = maxVariance / 2.0;
// Create a normal which is our standard normal + the normal map perturbation (which is going to be either positive or negative)
lowp vec3 normalAdjusted = vVaryingNormal + normalize(texture2D(normalMap, vTexCoords.st).rgb * maxVariance - minVariance);
// Calculate diffuse intensity
lowp float diffuseIntensity = max(0.0, dot(normalize(normalAdjusted), normalize(vVaryingLightDir)));
// Add the diffuse contribution blended with the standard texture lookup and add in the ambient light on top
lowp vec3 colour = (diffuseIntensity * diffuseColour.rgb) * texture2D(colourMap, vTexCoords.st).rgb + ambientColour.rgb;
// Set the almost final output color as a vec4 - only specular to go!
lowp vec4 vFragColour = vec4(colour, 1.0);
// Calc and apply specular contribution
lowp vec3 vReflection = normalize(reflect(-normalize(normalAdjusted), normalize(vVaryingLightDir)));
lowp float specularIntensity = max(0.0, dot(normalize(normalAdjusted), vReflection));
// If the diffuse light intensity is over a given value, then add the specular component
// Only calc the pow function when the diffuseIntensity is high (adding specular for high diffuse intensities only runs faster)
// Put this as 0 for accuracy, and something high like 0.98 for speed
if (diffuseIntensity > 0.98)
{
highp float fSpec = pow(specularIntensity, 64.0);
vFragColour.rgb += vec3(fSpec * specularColour.rgb);
}
gl_FragColor = vFragColour;
}
