yggdrasil75/stupidsimcpp
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pushing a star

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Yggdrasil75
2026-03-04 14:07:05 -05:00
parent 83989e955e
commit 4478bc1845
3 changed files with 133 additions and 9 deletions
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3
tests/planet.cpp
View File

@@ -167,6 +167,9 @@ public:
if (ImGui::CollapsingHeader("Celestial Bodies")) {
///TODO: add controls for moon, star.
if (ImGui::Button("Add Star", ImVec2(-1, 40))) {
sim.addStar();
}
}
if (ImGui::CollapsingHeader("Fillings")) {

73
util/grid/grid3eigen.hpp
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@@ -235,7 +235,7 @@ private:
float lodFalloffRate_ = 0.1f; // Lower = better, higher = worse. 0-1
float lodMinDistance_ = 100.0f;
float maxDistance_ = 4096;
float maxDistance_ = size * size;
struct Ray {
PointType origin;
@@ -339,7 +339,11 @@ private:
} else {
bool inserted = false;
for (int i = 0; i < 8; ++i) {
if (node->children[i] && boxIntersectsBox(node->children[i]->bounds, cubeBounds)) {
BoundingBox childBounds = createChildBounds(node, i);
if (boxIntersectsBox(childBounds, cubeBounds)) {
if (!node->children[i]) {
node->children[i] = std::make_unique<OctreeNode>(childBounds.first, childBounds.second);
}
inserted |= insertRecursive(node->children[i].get(), pointData, depth + 1);
}
}
@@ -369,6 +373,56 @@ private:
}
}
void ensureBounds(const BoundingBox& targetBounds) {
if (!root_) {
PointType center = (targetBounds.first + targetBounds.second) * 0.5f;
PointType size = targetBounds.second - targetBounds.first;
float maxDim = size.maxCoeff();
if (maxDim <= 0.0f) maxDim = 1.0f;
PointType halfSize = PointType::Constant(maxDim * 0.5f);
root_ = std::make_unique<OctreeNode>(center - halfSize, center + halfSize);
return;
}
while (true) {
bool xInside = root_->bounds.first.x() <= targetBounds.first.x() && root_->bounds.second.x() >= targetBounds.second.x();
bool yInside = root_->bounds.first.y() <= targetBounds.first.y() && root_->bounds.second.y() >= targetBounds.second.y();
bool zInside = root_->bounds.first.z() <= targetBounds.first.z() && root_->bounds.second.z() >= targetBounds.second.z();
if (xInside && yInside && zInside) {
break;
}
PointType min = root_->bounds.first;
PointType max = root_->bounds.second;
PointType size = max - min;
int expandX = (targetBounds.first.x() < min.x()) ? -1 : 1;
int expandY = (targetBounds.first.y() < min.y()) ? -1 : 1;
int expandZ = (targetBounds.first.z() < min.z()) ? -1 : 1;
PointType newMin = min;
PointType newMax = max;
if (expandX < 0) newMin.x() -= size.x(); else newMax.x() += size.x();
if (expandY < 0) newMin.y() -= size.y(); else newMax.y() += size.y();
if (expandZ < 0) newMin.z() -= size.z(); else newMax.z() += size.z();
auto newRoot = std::make_unique<OctreeNode>(newMin, newMax);
newRoot->isLeaf = false;
uint8_t oldOctant = 0;
if (expandX < 0) oldOctant |= 1;
if (expandY < 0) oldOctant |= 2;
if (expandZ < 0) oldOctant |= 4;
newRoot->children[oldOctant] = std::move(root_);
root_ = std::move(newRoot);
maxDepth++;
}
}
void ensureLOD(OctreeNode* node) {
std::lock_guard<std::mutex> lock(node->lodMutex);
if (node->lodData != nullptr) return;
@@ -1276,6 +1330,8 @@ public:
auto pointData = std::make_shared<NodeData>(data, pos, visible, cIdx, size, active, objectId, subId, mIdx);
ensureBounds(pointData->getCubeBounds());
if (insertRecursive(root_.get(), pointData, 0)) {
this->size++;
return true;
@@ -1478,6 +1534,7 @@ public:
}
if (matChanged) pointData->materialIdx = getMaterialIndex(mat);
ensureBounds(pointData->getCubeBounds());
bool res = insertRecursive(root_.get(), pointData, 0);
if(res) {
@@ -1496,6 +1553,7 @@ public:
removeRecursive(root_.get(), pointData->getCubeBounds(), pointData);
pointData->position = newPos;
ensureBounds(pointData->getCubeBounds());
if (insertRecursive(root_.get(), pointData, 0)) {
return true;
@@ -2118,10 +2176,17 @@ public:
collectNodesByObjectId(root_.get(), objectId, nodes);
if(nodes.empty()) return false;
for(auto& n : nodes) remove(n->position);
for(auto& n : nodes) {
if (removeRecursive(root_.get(), n->getCubeBounds(), n)) {
size--;
}
}
for(auto& n : nodes) {
n->position += offset;
insertRecursive(root_.get(), n, 0);
ensureBounds(n->getCubeBounds());
if (insertRecursive(root_.get(), n, 0)) {
size++;
}
}
for (auto& [key, mesh] : meshCache_) {

66
util/sim/planet.hpp
View File

@@ -26,7 +26,7 @@
#include "../stb/stb_image.h"
using v3 = Eigen::Vector3f;
using v3half = Eigen::Matrix<Eigen::half, 3, 1>; // 16-bit vector alias
using v3half = Eigen::Matrix<Eigen::half, 3, 1>;
const float Φ = M_PI * (3.0f - std::sqrt(5.0f));
enum class PlateType {
@@ -149,7 +149,7 @@ struct planetConfig {
float maxElevationRatio = 0.25f;
float gridSizeCube = 65536; //absolute max size for all nodes
float gridSizeCubeMin = 16384; //max size, if something leaves this, then it probably needs to be purged before it leaves the grid and becomes lost
float gridSizeCubeMin = 4096; //max size, if something leaves this, then it probably needs to be purged before it leaves the grid and becomes lost
float SMOOTHING_RADIUS = 1024.0f;
float REST_DENSITY = 0.00005f;
float TIMESTEP = 0.016f;
@@ -184,7 +184,7 @@ public:
planetsim() {
config = planetConfig();
grid = Octree<Particle>(v3(-config.gridSizeCube,-config.gridSizeCube,-config.gridSizeCube),v3(config.gridSizeCube,config.gridSizeCube,config.gridSizeCube), 16, 32);
grid = Octree<Particle>(v3(-config.gridSizeCubeMin,-config.gridSizeCubeMin,-config.gridSizeCubeMin),v3(config.gridSizeCubeMin,config.gridSizeCubeMin,config.gridSizeCubeMin), 16, 32);
}
float evaluate2DStack(const Eigen::Vector2f& point, const NoisePreviewState& state, PNoise2& gen) {
@@ -255,7 +255,7 @@ public:
}
config.currentStep = 1;
std::cout << "Step 1 done. base sphere generated" << std::endl;
grid.save("output/fibSphere");
grid.save("output/fibSphere.yggs");
}
inline void _applyNoise(std::function<float(const Eigen::Vector3f&)> noiseFunc) {
@@ -776,10 +776,66 @@ public:
}
grid.optimize();
std::cout << "Finalize apply results completed." << std::endl;
grid.save("output/plateworld.yggs");
}
void addStar() {
///TODO: add a star at roughly earth distance scaled based on planet radius.
TIME_FUNCTION;
const float realEarthRadiusKm = 6371.0f;
const float realSunRadiusKm = 696340.0f;
const float realAuKm = 149597870.0f;
float simScale = config.radius / realEarthRadiusKm;
float starRadius = realSunRadiusKm * simScale;
float orbitDistance = realAuKm * simScale;
std::cout << "--- STAR GENERATION ---" << std::endl;
std::cout << "Sim Scale: " << simScale << " units/km" << std::endl;
std::cout << "Star Radius: " << starRadius << " units" << std::endl;
std::cout << "Orbit Distance: " << orbitDistance << " units" << std::endl;
if (orbitDistance > config.gridSizeCube) {
std::cout << "[WARNING] Star distance (" << orbitDistance
<< ") exceeds octree bounds (" << config.gridSizeCube
<< "). Please increase gridSizeCube or the star will be outside the grid!" << std::endl;
}
v3 starCenter = config.center + v3(orbitDistance, 0.0f, 0.0f);
v3 starColor = v3(1.0f, 0.95f, 0.8f);
int starPoints = config.surfacePoints * 10;
for (int i = 0; i < starPoints; i++) {
float y = 1.0f - (i * 2.0f) / (starPoints - 1);
float radiusY = std::sqrt(1.0f - y * y);
float Θ = Φ * i;
float x = std::cos(Θ) * radiusY;
float z = std::sin(Θ) * radiusY;
v3 dir(x, y, z);
v3 pos = starCenter + dir * starRadius;
Particle pt;
pt.altPos = std::make_unique<AltPositions>();
pt.altPos->originalPos = pos.cast<Eigen::half>();
pt.altPos->noisePos = pos.cast<Eigen::half>();
pt.altPos->tectonicPos = pos.cast<Eigen::half>();
pt.currentPos = pos;
pt.originColor = starColor.cast<Eigen::half>();
pt.noiseDisplacement = 0.0f;
pt.surface = true;
pt.plateID = -2;
config.surfaceNodes.emplace_back(pt);
grid.set(pt, pt.currentPos, true, pt.originColor.cast<float>(), config.voxelSize, true, 2, 0, 1.0, 0.0f, 0.0f, 1.0f);
}
grid.optimize();
config.currentStep = 1;
std::cout << "Star generation complete. Placed " << starPoints << " nodes." << std::endl;
}
void addMoon() {