/**
* Shades a point with the same algorithm used by the {@link <a
* href="http://surf.sourceforge.net">surf raytracer</a>}.
*
* @param hitPoint Intersection point.
* @param v View vector (from intersection point to eye).
* @param n Surface normal.
* @param material Surface material.
* @return
*/
protected Color3f shadeWithMaterial(
Point3d hitPoint,
Vector3d v,
Vector3d n,
Color3f ambientColor,
LightProducts[] lightProducts) {
Vector3d l = new Vector3d();
Vector3d h = new Vector3d();
Color3f color = new Color3f(ambientColor);
for (int i = 0; i < dcsd.lightSources.length; i++) {
LightSource lightSource = dcsd.lightSources[i];
l.sub(lightSource.getPosition(), hitPoint);
l.normalize();
float lambertTerm = (float) n.dot(l);
if (lambertTerm > 0.0f) {
// compute diffuse color component
color.scaleAdd(lambertTerm, lightProducts[i].getDiffuseProduct(), color);
// compute specular color component
h.add(l, v);
h.normalize();
color.scaleAdd(
(float)
Math.pow(Math.max(0.0f, n.dot(h)), lightProducts[i].getMaterial().getShininess()),
lightProducts[i].getSpecularProduct(),
color);
}
}
color.clampMax(1.0f);
return color;
}
private Color3f antiAliasPixel(
double ll_u,
double ll_v,
double u_incr,
double v_incr,
AntiAliasingPattern aap,
Color3f ulColor,
Color3f urColor,
Color3f llColor,
Color3f lrColor,
HashMap<java.lang.Double, ColumnSubstitutorPair> csp_hm) {
// first average pixel-corner colors
Color3f finalColor;
// adaptive supersampling
float thresholdSqr = dcsd.antiAliasingThreshold * dcsd.antiAliasingThreshold;
if (aap != AntiAliasingPattern.OG_2x2
&& (colorDiffSqr(ulColor, urColor) >= thresholdSqr
|| colorDiffSqr(ulColor, llColor) >= thresholdSqr
|| colorDiffSqr(ulColor, lrColor) >= thresholdSqr
|| colorDiffSqr(urColor, llColor) >= thresholdSqr
|| colorDiffSqr(urColor, lrColor) >= thresholdSqr
|| colorDiffSqr(llColor, lrColor) >= thresholdSqr)) {
// anti-alias pixel with advanced sampling pattern
finalColor = new Color3f();
for (SamplingPoint sp : aap) {
if (Thread.interrupted()) throw new RenderingInterruptedException();
Color3f ss_color;
if (sp.getU() == 0.0 && sp.getV() == 0.0) ss_color = llColor;
else if (sp.getU() == 0.0 && sp.getV() == 1.0) ss_color = ulColor;
else if (sp.getU() == 1.0 && sp.getV() == 1.0) ss_color = urColor;
else if (sp.getU() == 1.0 && sp.getV() == 0.0) ss_color = lrColor;
else {
// color of this sample point is not known -> calculate
double v = ll_v + sp.getV() * v_incr;
double u = ll_u + sp.getU() * u_incr;
ColumnSubstitutorPair csp = csp_hm.get(v);
if (csp == null) {
csp =
new ColumnSubstitutorPair(
dcsd.surfaceRowSubstitutor.setV(v), dcsd.gradientRowSubstitutor.setV(v));
csp_hm.put(v, csp);
}
ss_color = tracePolynomial(csp.scs, csp.gcs, u, v);
}
finalColor.scaleAdd(sp.getWeight(), ss_color, finalColor);
if (false)
return new Color3f(
0, 0, 0); // paint pixels, that are supposed to be anti-aliased in black
}
} else {
finalColor = new Color3f(ulColor);
finalColor.add(urColor);
finalColor.add(llColor);
finalColor.add(lrColor);
finalColor.scale(0.25f);
}
// clamp color, because floating point operations may yield values outside [0,1]
finalColor.clamp(0f, 1f);
return finalColor;
}