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reworked Scene::traceRayRecurse() to handle backfaces properly for refraction

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git-svn-id: svn://anubis/fart/trunk@378 7f9b0f55-74a9-4bce-be96-3c2cd072584d
This commit is contained in:
Josh Holtrop 2010-10-12 16:39:29 +00:00
parent b24aea4dba
commit 1d5d043928
2 changed files with 76 additions and 48 deletions
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30
main/Scene.cc
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@ -119,8 +119,7 @@ void Scene::renderPixel(int x, int y, unsigned char * pixel)
Color Scene::traceRay(const Ray & ray)
{
static refptr<Material> air = new Material();
return traceRayRecurse(ray, m_max_depth, 1.0, air);
return traceRayRecurse(ray, m_max_depth, 1.0, NULL);
}
/**
@ -129,7 +128,11 @@ Color Scene::traceRay(const Ray & ray)
Color Scene::traceRayRecurse(const Ray & ray, int depth, double factor,
refptr<Material> last_material)
{
Color color;
static refptr<Material> air = new Material();
Color color(0, 0, 0);
if (last_material.isNull())
last_material = air;
Shape::Intersection hit = getRayClosestHit(ray);
@ -139,12 +142,10 @@ Color Scene::traceRayRecurse(const Ray & ray, int depth, double factor,
refptr<Material> material = hit.shape->getMaterial();
/* check for backfaces */
if (ray.getDirection() % hit.normal > 0.0)
{
/* if dot product is positive, this is a back-face */
hit.normal = -hit.normal;
}
bool frontface = ray.getDirection() % hit.normal < 0.0;
if (frontface)
{
color = computePhong(material,
ray,
hit.position,
@ -187,6 +188,19 @@ Color Scene::traceRayRecurse(const Ray & ray, int depth, double factor,
}
}
}
else
{
material = air;
Vector jitter_surface_point = hit.position
+ ray.getDirection() * 0.0001;
Vector refracted_direction =
ray.getDirection().refract(-hit.normal,
last_material->getRefraction(),
material->getRefraction());
Ray newRay(jitter_surface_point, refracted_direction);
color = traceRayRecurse(newRay, depth, factor, material);
}
}
return color;
}

16
scenes/for-test.fart
View File

@ -3,7 +3,7 @@ scene
{
camera
{
position <0, 0, 40>
position <0, -40, 40>
look_at <0, 100, 5>
}
@ -17,6 +17,12 @@ scene
color <0, 0.8, 1>
}
define material glass
{
transparency 1
refraction 1.5
}
plane
{
position <0, 0, 1>, 0
@ -34,8 +40,16 @@ scene
{
radius 10
translate <$x, $y, 10>
if ($x == 0 && $y == 0)
{
material glass
translate <0, 0, 20>
}
else
{
material mat
}
}
}
}
}