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voxel-raycaster
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Fiddling with the traversal algorithm and shoehorning in the DFS algo

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master
MitchellHansen 7 years ago
parent 316293a110
commit 4642ab8f0b
4 changed files with 50 additions and 67 deletions
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2
include/map/Octree.h
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@ -18,8 +18,6 @@ struct OctState {
// ====== DEBUG =======
char found = 1;
};

3
kernels/ray_caster_kernel.cl
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@ -215,8 +215,7 @@ __kernel void raycaster(
float3 intersection_t = delta_t * ((*cam_pos) - floor(*cam_pos)) * convert_float3(voxel_step);
// for negative values, wrap around the delta_t
intersection_t += delta_t * -convert_float3(isless(intersection_t, 0));
intersection_t -= delta_t * convert_float3(isless(intersection_t, 0));
int dist = 0;
int3 face_mask = { 0, 0, 0 };

108
src/map/Map.cpp
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@ -25,8 +25,8 @@ Map::Map(uint32_t dimensions) {
octree.Validate(voxel_data, dim3);
sf::Vector2f cam_dir(2, 0.01);
sf::Vector3f cam_pos(10, 10, 10);
sf::Vector2f cam_dir(0.95, 0.81);
sf::Vector3f cam_pos(10.5, 10.5, 10.5);
std::vector<std::tuple<sf::Vector3i, char>> list1 = CastRayCharArray(voxel_data, &dim3, &cam_dir, &cam_pos);
std::vector<std::tuple<sf::Vector3i, char>> list2 = CastRayOctree(&octree, &dim3, &cam_dir, &cam_pos);
@ -99,9 +99,9 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayCharArray(
);
// for negative values, wrap around the delta_t
intersection_t.x += delta_t.x * -(std::min(intersection_t.x, 0.0f));
intersection_t.y += delta_t.y * -(std::min(intersection_t.y, 0.0f));
intersection_t.z += delta_t.z * -(std::min(intersection_t.z, 0.0f));
intersection_t.x -= delta_t.x * (std::min(intersection_t.x, 0.0f));
intersection_t.y -= delta_t.y * (std::min(intersection_t.y, 0.0f));
intersection_t.z -= delta_t.z * (std::min(intersection_t.z, 0.0f));
int dist = 0;
@ -115,7 +115,6 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayCharArray(
face_mask.y = intersection_t.y <= std::min(intersection_t.z, intersection_t.x);
face_mask.z = intersection_t.z <= std::min(intersection_t.x, intersection_t.y);
intersection_t.x += delta_t.x * fabs(face_mask.x);
intersection_t.y += delta_t.y * fabs(face_mask.y);
intersection_t.z += delta_t.z * fabs(face_mask.z);
@ -124,31 +123,6 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayCharArray(
voxel.y += voxel_step.y * face_mask.y;
voxel.z += voxel_step.z * face_mask.z;
if ((intersection_t.x) < (intersection_t.y)) {
if ((intersection_t.x) < (intersection_t.z)) {
voxel.x += voxel_step.x;
intersection_t.x = intersection_t.x + delta_t.x;
}
else {
voxel.z += voxel_step.z;
intersection_t.z = intersection_t.z + delta_t.z;
}
}
else {
if ((intersection_t.y) < (intersection_t.z)) {
voxel.y += voxel_step.y;
intersection_t.y = intersection_t.y + delta_t.y;
}
else {
voxel.z += voxel_step.z;
intersection_t.z = intersection_t.z + delta_t.z;
}
}
if (voxel.x >= map_dim->x || voxel.y >= map_dim->y || voxel.z >= map_dim->z) {
return travel_path;
}
@ -179,6 +153,15 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayOctree(
sf::Vector3f* cam_pos
) {
// Setup the voxel coords from the camera origin
sf::Vector3i voxel(*cam_pos);
// THIS DOES NOT HAVE TO RETURN TRUE ON FOUND
// This function when passed a "air" voxel will return as far down
// the IDX stack as it could go. We use this oct-level to determine
// our first position and jump. Updating it as we go
OctState traversal_state = octree->GetVoxel(voxel);
std::vector<std::tuple<sf::Vector3i, char>> travel_path;
sf::Vector3f ray_dir(1, 0, 0);
@ -197,6 +180,13 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayOctree(
ray_dir.z
);
// correct for the base ray pointing to (1, 0, 0) as (0, 0). Should equal (1.57, 0)
ray_dir = sf::Vector3f(
static_cast<float>(ray_dir.z * sin(-1.57) + ray_dir.x * cos(-1.57)),
static_cast<float>(ray_dir.y),
static_cast<float>(ray_dir.z * cos(-1.57) - ray_dir.x * sin(-1.57))
);
// Setup the voxel step based on what direction the ray is pointing
sf::Vector3i voxel_step(1, 1, 1);
@ -205,8 +195,10 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayOctree(
voxel_step.y *= (ray_dir.y > 0) - (ray_dir.y < 0);
voxel_step.z *= (ray_dir.z > 0) - (ray_dir.z < 0);
// Setup the voxel coords from the camera origin
sf::Vector3i voxel(*cam_pos);
// set the jump multiplier based on the traversal state vs the log base 2 of the maps dimensions
int jump_power = 1;
if (log2(map_dim->x) != traversal_state.scale)
jump_power = pow(2, traversal_state.scale);
// Delta T is the units a ray must travel along an axis in order to
// traverse an integer split
@ -216,9 +208,16 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayOctree(
fabs(1.0f / ray_dir.z)
);
delta_t *= static_cast<float>(jump_power);
// offset is how far we are into a voxel, enables sub voxel movement
// Intersection T is the collection of the next intersection points
// for all 3 axis XYZ.
// TODO: start here
// set intersection t to the current hierarchy level each time we change levels
// and use that to step
sf::Vector3f intersection_t(
delta_t.x * (cam_pos->y - floor(cam_pos->x)) * voxel_step.x,
delta_t.y * (cam_pos->x - floor(cam_pos->y)) * voxel_step.y,
@ -226,56 +225,43 @@ std::vector<std::tuple<sf::Vector3i, char>> Map::CastRayOctree(
);
// for negative values, wrap around the delta_t
intersection_t.x += delta_t.x * -(std::min(intersection_t.x, 0.0f));
intersection_t.y += delta_t.y * -(std::min(intersection_t.y, 0.0f));
intersection_t.z += delta_t.z * -(std::min(intersection_t.z, 0.0f));
intersection_t.x -= delta_t.x * (std::isless(intersection_t.x, 0.0f));
intersection_t.y -= delta_t.y * (std::isless(intersection_t.y, 0.0f));
intersection_t.z -= delta_t.z * (std::isless(intersection_t.z, 0.0f));
int dist = 0;
sf::Vector3i face_mask(0, 0, 0);
int voxel_data = 0;
OctState traversal_state = octree->GetVoxel(voxel);
// Andrew Woo's raycasting algo
do {
// check which direction we step in
face_mask.x = intersection_t.x <= std::min(intersection_t.y, intersection_t.z);
face_mask.y = intersection_t.y <= std::min(intersection_t.z, intersection_t.x);
face_mask.z = intersection_t.z <= std::min(intersection_t.x, intersection_t.y);
// Increment the selected directions intersection, abs the face_mask to stay within the algo constraints
intersection_t.x += delta_t.x * fabs(face_mask.x);
intersection_t.y += delta_t.y * fabs(face_mask.y);
intersection_t.z += delta_t.z * fabs(face_mask.z);
voxel.x += voxel_step.x * face_mask.x;
voxel.y += voxel_step.y * face_mask.y;
voxel.z += voxel_step.z * face_mask.z;
// step the voxel direction
voxel.x += voxel_step.x * face_mask.x * jump_power;
voxel.y += voxel_step.y * face_mask.y * jump_power;
voxel.z += voxel_step.z * face_mask.z * jump_power;
if ((intersection_t.x) < (intersection_t.y)) {
if ((intersection_t.x) < (intersection_t.z)) {
voxel.x += voxel_step.x;
intersection_t.x = intersection_t.x + delta_t.x;
}
else {
if (face_mask.x != 0) {
voxel.z += voxel_step.z;
intersection_t.z = intersection_t.z + delta_t.z;
}
}
else {
if ((intersection_t.y) < (intersection_t.z)) {
if (face_mask.y != 0) {
voxel.y += voxel_step.y;
intersection_t.y = intersection_t.y + delta_t.y;
}
else {
}
if (face_mask.z != 0) {
voxel.z += voxel_step.z;
intersection_t.z = intersection_t.z + delta_t.z;
}
}
if (voxel.x >= map_dim->x || voxel.y >= map_dim->y || voxel.z >= map_dim->z) {

2
src/map/Octree.cpp
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@ -93,7 +93,7 @@ OctState Octree::GetVoxel(sf::Vector3i position) {
mask_index += 2;
// What is up with the binary operator on this one? TODO
// TODO What is up with the binary operator on this one?
state.idx_stack[state.scale] ^= idx_set_y_mask;
}

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