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Basic ray/voxel intersection testing up and running.

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This commit is contained in:
Andrzej Kapolka 2014-10-10 15:11:37 -07:00
parent c8c09a1e7b
commit 1911cfd0be
2 changed files with 62 additions and 23 deletions
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76
interface/src/MetavoxelSystem.cpp
View file

@ -354,9 +354,8 @@ int RayVoxelIntersectionVisitor::visit(MetavoxelInfo& info, float distance) {
if (!buffer) {
return STOP_RECURSION;
}
glm::vec3 origin = ((_origin + distance * _direction) - info.minimum) / info.size;
if (buffer->findFirstRayIntersection(origin, _direction, intersectionDistance)) {
intersectionDistance = intersectionDistance * info.size + distance;
glm::vec3 entry = ((_origin + distance * _direction) - info.minimum) / info.size;
if (buffer->findFirstRayIntersection(entry, _origin, _direction, intersectionDistance)) {
return SHORT_CIRCUIT;
}
return STOP_RECURSION;
@ -1035,11 +1034,11 @@ void VoxelPoint::setNormal(const glm::vec3& normal) {
}
VoxelBuffer::VoxelBuffer(const QVector<VoxelPoint>& vertices, const QVector<int>& indices, const QVector<glm::vec3>& hermite,
const QHash<QRgb, glm::vec3>& points, int size, const QVector<SharedObjectPointer>& materials) :
const QMultiHash<QRgb, int>& quadIndices, int size, const QVector<SharedObjectPointer>& materials) :
_vertices(vertices),
_indices(indices),
_hermite(hermite),
_points(points),
_quadIndices(quadIndices),
_size(size),
_vertexCount(vertices.size()),
_indexCount(indices.size()),
@ -1048,17 +1047,47 @@ VoxelBuffer::VoxelBuffer(const QVector<VoxelPoint>& vertices, const QVector<int>
_materials(materials) {
}
bool VoxelBuffer::findFirstRayIntersection(const glm::vec3& origin, const glm::vec3& direction, float& distance) const {
static bool findRayTriangleIntersection(const glm::vec3& origin, const glm::vec3& direction,
const glm::vec3& v0, const glm::vec3& v1, const glm::vec3& v2, float& distance) {
glm::vec3 firstSide = v0 - v1;
glm::vec3 secondSide = v2 - v1;
glm::vec3 normal = glm::cross(secondSide, firstSide);
float dividend = glm::dot(normal, v1) - glm::dot(origin, normal);
if (dividend > 0.0f) {
return false; // origin below plane
}
float divisor = glm::dot(normal, direction);
if (divisor > -EPSILON) {
return false;
}
float t = dividend / divisor;
glm::vec3 point = origin + direction * t;
if (glm::dot(normal, glm::cross(point - v1, firstSide)) > 0.0f &&
glm::dot(normal, glm::cross(secondSide, point - v1)) > 0.0f &&
glm::dot(normal, glm::cross(point - v0, v2 - v0)) > 0.0f) {
distance = t;
return true;
}
return false;
}
bool VoxelBuffer::findFirstRayIntersection(const glm::vec3& entry, const glm::vec3& origin,
const glm::vec3& direction, float& distance) const {
float highest = _size - 1.0f;
glm::vec3 position = origin * highest;
glm::vec3 position = entry * highest;
glm::vec3 floors = glm::floor(position);
int max = _size - 2;
int x = qMin((int)floors.x, max), y = qMin((int)floors.y, max), z = qMin((int)floors.z, max);
float combinedDistance = 0.0f;
forever {
if (_points.contains(qRgb(x + 1, y + 1, z + 1))) {
distance = combinedDistance / highest;
return true;
for (QMultiHash<QRgb, int>::const_iterator it = _quadIndices.constFind(qRgb(x + 1, y + 1, z + 1));
it != _quadIndices.constEnd(); it++) {
const int* indices = _indices.constData() + *it;
if (findRayTriangleIntersection(origin, direction, _vertices.at(indices[0]).vertex,
_vertices.at(indices[1]).vertex, _vertices.at(indices[2]).vertex, distance) ||
findRayTriangleIntersection(origin, direction, _vertices.at(indices[0]).vertex,
_vertices.at(indices[2]).vertex, _vertices.at(indices[3]).vertex, distance)) {
return true;
}
}
float xDistance = FLT_MAX, yDistance = FLT_MAX, zDistance = FLT_MAX;
if (direction.x > 0.0f) {
@ -1105,7 +1134,6 @@ bool VoxelBuffer::findFirstRayIntersection(const glm::vec3& origin, const glm::v
}
}
position += direction * minimumDistance;
combinedDistance += minimumDistance;
}
return false;
}
@ -1115,13 +1143,11 @@ void VoxelBuffer::render(bool cursor) {
_vertexBuffer.create();
_vertexBuffer.bind();
_vertexBuffer.allocate(_vertices.constData(), _vertices.size() * sizeof(VoxelPoint));
_vertices.clear();
_indexBuffer.create();
_indexBuffer.bind();
_indexBuffer.allocate(_indices.constData(), _indices.size() * sizeof(int));
_indices.clear();
if (!_materials.isEmpty()) {
_networkTextures.resize(_materials.size());
for (int i = 0; i < _materials.size(); i++) {
@ -1735,7 +1761,7 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
QVector<VoxelPoint> vertices;
QVector<int> indices;
QVector<glm::vec3> hermiteSegments;
QHash<QRgb, glm::vec3> points;
QMultiHash<QRgb, int> quadIndices;
// see http://www.frankpetterson.com/publications/dualcontour/dualcontour.pdf for a description of the
// dual contour algorithm for generating meshes from voxel data using Hermite-tagged edges
@ -2142,8 +2168,6 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
{ (quint8)materialWeights[0], (quint8)materialWeights[1], (quint8)materialWeights[2],
(quint8)materialWeights[3] } };
points.insert(qRgb(x + 1, y + 1, z + 1), (glm::vec3(clampedX, clampedY, clampedZ) + center) / highest);
// determine whether we must "crease" by generating directional normals
const float CREASE_COS_NORMAL = glm::cos(glm::radians(40.0f));
AxisIndex index(vertices.size(), vertices.size(), vertices.size());
@ -2202,6 +2226,10 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
// quads for each edge that includes a transition, using indices of previously generated vertices
if (x != 0 && y != 0 && z != 0) {
if (alpha0 != alpha1) {
quadIndices.insert(qRgb(x, y, z), indices.size());
quadIndices.insert(qRgb(x, y - 1, z), indices.size());
quadIndices.insert(qRgb(x, y - 1, z - 1), indices.size());
quadIndices.insert(qRgb(x, y, z - 1), indices.size());
indices.append(index.x);
int index1 = lastLineIndices.at(x).x;
int index2 = lastPlaneIndices.at((y - 1) * expanded + x).x;
@ -2218,6 +2246,10 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
}
if (alpha0 != alpha2) {
quadIndices.insert(qRgb(x, y, z), indices.size());
quadIndices.insert(qRgb(x - 1, y, z), indices.size());
quadIndices.insert(qRgb(x - 1, y, z - 1), indices.size());
quadIndices.insert(qRgb(x, y, z - 1), indices.size());
indices.append(index.y);
int index1 = lastIndex.y;
int index2 = lastPlaneIndices.at(y * expanded + x - 1).y;
@ -2234,6 +2266,10 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
}
if (alpha0 != alpha4) {
quadIndices.insert(qRgb(x, y, z), indices.size());
quadIndices.insert(qRgb(x - 1, y, z), indices.size());
quadIndices.insert(qRgb(x - 1, y - 1, z), indices.size());
quadIndices.insert(qRgb(x, y - 1, z), indices.size());
indices.append(index.z);
int index1 = lastIndex.z;
int index2 = lastLineIndices.at(x - 1).z;
@ -2269,7 +2305,7 @@ int VoxelAugmentVisitor::visit(MetavoxelInfo& info) {
colorZ += area;
}
}
buffer = new VoxelBuffer(vertices, indices, hermiteSegments, points, size,
buffer = new VoxelBuffer(vertices, indices, hermiteSegments, quadIndices, size,
material ? material->getMaterials() : QVector<SharedObjectPointer>());
}
BufferDataPointer pointer(buffer);

9
interface/src/MetavoxelSystem.h
View file

@ -243,10 +243,13 @@ class VoxelBuffer : public BufferData {
public:
VoxelBuffer(const QVector<VoxelPoint>& vertices, const QVector<int>& indices, const QVector<glm::vec3>& hermite,
const QHash<QRgb, glm::vec3>& points, int size, const QVector<SharedObjectPointer>& materials =
const QMultiHash<QRgb, int>& quadIndices, int size, const QVector<SharedObjectPointer>& materials =
QVector<SharedObjectPointer>());
bool findFirstRayIntersection(const glm::vec3& origin, const glm::vec3& direction, float& distance) const;
/// Finds the first intersection between the described ray and the voxel data.
/// \param entry the entry point of the ray in relative coordinates, from (0, 0, 0) to (1, 1, 1)
bool findFirstRayIntersection(const glm::vec3& entry, const glm::vec3& origin,
const glm::vec3& direction, float& distance) const;
virtual void render(bool cursor = false);
@ -255,7 +258,7 @@ private:
QVector<VoxelPoint> _vertices;
QVector<int> _indices;
QVector<glm::vec3> _hermite;
QHash<QRgb, glm::vec3> _points;
QMultiHash<QRgb, int> _quadIndices;
int _size;
int _vertexCount;
int _indexCount;