Merge pull request #953 from sma-github/ray-plane-intersection

bugfix for intersection ray/plane, added related tests #953
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Christophe 2019-09-30 09:57:37 +02:00 committed by GitHub
commit ea678faff9
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2 changed files with 40 additions and 3 deletions

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@ -13,11 +13,14 @@ namespace glm
typename genType::value_type d = glm::dot(dir, planeNormal); typename genType::value_type d = glm::dot(dir, planeNormal);
typename genType::value_type Epsilon = std::numeric_limits<typename genType::value_type>::epsilon(); typename genType::value_type Epsilon = std::numeric_limits<typename genType::value_type>::epsilon();
if(d < -Epsilon) if(glm::abs(d) > Epsilon) // if dir and planeNormal are not perpendicular
{ {
intersectionDistance = glm::dot(planeOrig - orig, planeNormal) / d; typename genType::value_type const tmp_intersectionDistance = glm::dot(planeOrig - orig, planeNormal) / d;
if (tmp_intersectionDistance > static_cast<typename genType::value_type>(0)) { // allow only intersections
intersectionDistance = tmp_intersectionDistance;
return true; return true;
} }
}
return false; return false;
} }

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@ -3,6 +3,39 @@
#include <glm/gtc/epsilon.hpp> #include <glm/gtc/epsilon.hpp>
#include <glm/gtx/intersect.hpp> #include <glm/gtx/intersect.hpp>
int test_intersectRayPlane()
{
int Error = 0;
glm::vec3 const PlaneOrigin(0, 0, 1);
glm::vec3 const PlaneNormal(0, 0, -1);
glm::vec3 const RayOrigin(0, 0, 0);
glm::vec3 const RayDir(0, 0, 1);
// check that inversion of the plane normal has no effect
{
float Distance = 0;
bool const Result = glm::intersectRayPlane(RayOrigin, RayDir, PlaneOrigin, PlaneNormal, Distance);
Error += glm::abs(Distance - 1.f) <= std::numeric_limits<float>::epsilon() ? 0 : 1;
Error += Result ? 0 : 1;
}
{
float Distance = 0;
bool const Result = glm::intersectRayPlane(RayOrigin, RayDir, PlaneOrigin, -1.f * PlaneNormal, Distance);
Error += glm::abs(Distance - 1.f) <= std::numeric_limits<float>::epsilon() ? 0 : 1;
Error += Result ? 0 : 1;
}
// check if plane is before of behind the ray origin
{
float Distance = 9.9999f; // value should not be changed
bool const Result = glm::intersectRayPlane(RayOrigin, RayDir, -1.f * PlaneOrigin, PlaneNormal, Distance);
Error += glm::abs(Distance - 9.9999f) <= std::numeric_limits<float>::epsilon() ? 0 : 1;
Error += Result ? 1 : 0; // there is no intersection in front of the ray origin, only behind
}
return Error;
}
int test_intersectRayTriangle() int test_intersectRayTriangle()
{ {
int Error = 0; int Error = 0;
@ -47,6 +80,7 @@ int main()
{ {
int Error = 0; int Error = 0;
Error += test_intersectRayPlane();
Error += test_intersectRayTriangle(); Error += test_intersectRayTriangle();
Error += test_intersectLineTriangle(); Error += test_intersectLineTriangle();