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Collision affects velocity correctly, no wierd ice cream sliding along walls.

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This commit is contained in:
William Moberg
2016-02-02 17:19:59 +01:00
parent 796e3eac79
commit affcc5305b
1 changed files with 30 additions and 18 deletions
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src/Engine/Collision/Collision.cpp
+30 -18
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@@ -344,9 +344,10 @@ constexpr float SlopeConstant(float degrees)
//An array containing 3 int pairs { 0, 2 }, { 0, 1 }, { 1, 2 }
constexpr std::array<std::pair<int, int>, 3> dimensionPairs({ std::pair<int, int>(0, 2), std::pair<int, int>(0, 1), std::pair<int, int>(1, 2) });
//TODO: Prefer to move in y - if the resolution is small enough, value in physics comp.
//TODO: Walking down slopes correctly.
bool AABBvsTriangle(const AABB& box,
const std::array<glm::vec3, 3>& triPos,
const glm::vec3& wantDirection,
glm::vec3& boxVelocity,
glm::vec3& outVector)
{
@@ -354,7 +355,7 @@ bool AABBvsTriangle(const AABB& box,
//Also, don't check a triangle facing away from the player.
//Less checks, and we should be able to walk out from models if we are trapped inside.
glm::vec3 triNormal = glm::cross(triPos[1] - triPos[0], triPos[2] - triPos[0]);
if (!vectorHasLength(triNormal) || (glm::dot(triNormal, boxVelocity) > 0) && vectorHasLength(boxVelocity)) {
if (!vectorHasLength(triNormal) || (glm::dot(triNormal, boxVelocity) > 0)) {
return false;
}
@@ -428,40 +429,56 @@ bool AABBvsTriangle(const AABB& box,
{
//If we get here, the resolution is along one coordinate axis.
//set velocity to 0 in that dimension.
//projNorm = glm::vec3(0.f);
//projNorm[resolveCase] = 1;
//ImGui::Text(("Axis " + std::string(projNorm.y > SlopeConstant(45.0f) ? "Ground" : "Slope") + "collision proj=(%f,%f,%f)").c_str(), projNorm.x, projNorm.y, projNorm.z);
boxVelocity[resolveCase] = 0.f;
return true;
}
case Line:
projNorm = glm::normalize(outVector);
//ImGui::Text(("Line " + std::string(projNorm.y > SlopeConstant(45.0f) ? "Ground" : "Slope") + "collision proj=(%f,%f,%f)").c_str(), projNorm.x, projNorm.y, projNorm.z);
break;
case Corner:
projNorm = triNormal;
//ImGui::Text(("Corner " + std::string(projNorm.y > SlopeConstant(45.0f) ? "Ground" : "Slope") + "collision proj=(%f,%f,%f)").c_str(), projNorm.x, projNorm.y, projNorm.z);
break;
default:
break;
}
//Project the velocity onto the normal of the hit line/face.
//w = v - <v,n>*n, |n|==1.
boxVelocity = boxVelocity - glm::dot(boxVelocity, projNorm) * projNorm;
//If the collision was not on steep wall or similarly (e.g. walking on the ground), do special treatment.
//Magic value that makes condition correspond to:
//if the angle between horizon and the collision surface is less than 45 degrees.
if (projNorm.y > SlopeConstant(45.0f)) {
//Make sure the player keeps moving in their desired direction, just slower.
float len = glm::length2(boxVelocity);
if (len > 0.0001f) {
boxVelocity = glm::sqrt(len) * wantDirection;
}
//Ensure that the player always is moved upwards, instead of sliding down.
len = glm::length(outVector);
//Also zero the vertical velocity.
float len = glm::length(outVector);
float ang = glm::half_pi<float>() - glm::acos(outVector.y / len);
if (len > 0.0000001f && ang > 0.0000001f) {
outVector.x = 0;
outVector.y = len / glm::sin(ang);
outVector.z = 0;
boxVelocity.y = 0.f;
}
} else if (projNorm.y > 0) {
//Enter here if the triangle is a steep slope, and it is not facing downwards.
//Project the velocity onto the normal of the hit line/face.
//w = v - <v,n>*n, |n|==1.
boxVelocity = boxVelocity - glm::dot(boxVelocity, projNorm) * projNorm;
//Ensure that the player will be pushed in the xz-plane.
//glm::vec3 moveDir(outVector);
//moveDir.y = 0;
//if (vectorHasLength(moveDir)) {
// moveDir = glm::normalize(moveDir);
// float len = glm::length(outVector);
// float dotMoveOut = moveDir.x * outVector.x + moveDir.z * outVector.z;
// float ang = glm::half_pi<float>() - glm::acos(dotMoveOut / len);
// if (len > 0.0000001f && ang > 0.0000001f) {
// outVector = (len / glm::sin(ang)) * moveDir;
// }
//}
}
return true;
}
@@ -477,11 +494,6 @@ bool AABBvsTriangles(const AABB& box,
AABB newBox = box;
outResolutionVector = glm::vec3(0.f);
glm::vec3 wantDirection(boxVelocity);
wantDirection.y = 0;
if (vectorHasLength(wantDirection)) {
wantDirection = glm::normalize(wantDirection);
}
for (int i = 0; i < modelIndices.size(); ) {
std::array<glm::vec3, 3> triVertices = {
Transform::TransformPoint(modelVertices[modelIndices[i++]].Position, modelMatrix),
@@ -489,7 +501,7 @@ bool AABBvsTriangles(const AABB& box,
Transform::TransformPoint(modelVertices[modelIndices[i++]].Position, modelMatrix)
};
glm::vec3 outVec;
if (AABBvsTriangle(newBox, triVertices, wantDirection, boxVelocity, outVec)) {
if (AABBvsTriangle(newBox, triVertices, boxVelocity, outVec)) {
hit = true;
outResolutionVector += outVec;
newBox = AABB::FromOriginSize(newBox.Origin() + outVec, newBox.Size());