Voxelization.java: does not initialize all voxels by default for more conservative memory usage.

AMAPVox/AMAPVoxCore/src/main/java/fr/amap/lidar/amapvox/commons/Voxel.java

@@ -53,10 +53,6 @@ public class Voxel {
      * mean ray length (cumulated ray length / nbSampling)
      */
     public double lMeanTotal;
-    /**
-     * approximated transmittance
-     */
-    public double approxTransm;
     /**
      * numerically estimated transmittance
      */
@@ -89,7 +85,7 @@ public class Voxel {
     // variable for numerical estimation of the transmittance
     public List<TrRecord> trRecords;
     public boolean fallbackTransm = false;
-    
+
     /**
      * mean distance to laser
      */
@@ -115,9 +111,6 @@ public class Voxel {
      */
     public double explorationRate;
 
-    public Voxel() {
-    }
-
     public static enum MergeMode {
 
         SUM,
@@ -236,6 +229,21 @@ public class Voxel {
         attenuationVar = new Attenuation();
     }
 
+    /**
+     * Set some variables to NaN (zero could be ambiguous as it does not convey
+     * the same meaning than NaN).
+     */
+    public void empty() {
+
+        angleMean = Double.NaN;
+        PadBVTotal = Double.NaN;
+        transmittance = Double.NaN;
+        distLaser = Double.NaN;
+        attenuation_biasCorr = Double.NaN;
+        attenuation = Double.NaN;
+        explorationRate = Double.NaN;
+    }
+
     public String variablesToString(String[] names, DecimalFormat dnf) {
 
         // voxel attributes to String
@@ -267,7 +275,7 @@ public class Voxel {
 
         return voxelSB.toString().trim();
     }
-    
+
     public void addTrRecord(double bfIn, double rayLength) {
         trRecords.add(new TrRecord(bfIn, rayLength));
     }

AMAPVox/AMAPVoxCore/src/main/java/fr/amap/lidar/amapvox/voxelisation/Voxelization.java

@@ -181,7 +181,9 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
 
     /**
      * Propagate a {@code shot} in the voxel space ignoring the vegetation in
-     * order to estimate a potential beam volume.
+     * order to estimate a potential beam volume. The method is also in charge
+     * of initialising the voxels since any voxel that will be crossed during
+     * free propagation may be crossed as well during propagation.
      *
      * @param shot
      */
@@ -196,6 +198,9 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
             do {
                 // current voxel
                 Point3i vcoord = context.indices;
+                if (null == voxels[vcoord.x][vcoord.y][vcoord.z]) {
+                    voxels[vcoord.x][vcoord.y][vcoord.z] = initVoxel(vcoord.x, vcoord.y, vcoord.z);
+                }
 
                 // stop propagation if current voxel is below the ground
                 if (belowGround(voxels[vcoord.x][vcoord.y][vcoord.z])) {
@@ -348,6 +353,9 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
 
                 // increment ground energy
                 if (groundEnergyEnabled && closeToGround(voxels[i][j][k])) {
+                    if (null == groundEnergy[i][j]) {
+                        groundEnergy[i][j] = new GroundEnergy();
+                    }
                     groundEnergy[i][j].groundEnergyPotential++;
                     groundEnergy[i][j].groundEnergyActual += beamFractionIn;
                 }
@@ -676,8 +684,8 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
             dtm = Util.loadDTM(cfg.getVoxelParameters().getDtmFilteringParams().getDtmFile());
             if (dtm != null && cfg.getVoxelParameters().getDtmFilteringParams().isUseVOPMatrix()) {
                 Matrix4d vop = (null == cfg.getVopMatrix())
-                ? MatrixUtility.identity4d()
-                : new Matrix4d(cfg.getVopMatrix());
+                        ? MatrixUtility.identity4d()
+                        : new Matrix4d(cfg.getVopMatrix());
                 dtm.setTransformationMatrix(vop);
             }
         }
@@ -867,24 +875,19 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
                         return;
                     }
                     // empty voxel, no post-processing
+                    if (null == voxels[i][j][k]) {
+                        continue;
+                    }
+                    // unsampled voxel, no post-processing
+                    // (may have a non zero potential beam surface though, so it
+                    // may not be empty)
                     if (voxels[i][j][k].nbSampling == 0) {
-                        voxels[i][j][k].angleMean = Double.NaN;
-                        voxels[i][j][k].approxTransm = Double.NaN;
-                        voxels[i][j][k].PadBVTotal = Double.NaN;
-                        if (numEstimTransmEnabled) {
-                            voxels[i][j][k].transmittance = Double.NaN;
-                        }
-                        if (wdistLaserEnabled) {
-                            voxels[i][j][k].distLaser = Double.NaN;
-                        }
-                        voxels[i][j][k].attenuation_biasCorr = Double.NaN;
-                        voxels[i][j][k].attenuation = Double.NaN;
-                        if (subSamplingEnabled) {
-                            voxels[i][j][k].explorationRate = Double.NaN;
-                        }
+                        // set to NaN some of the variables
+                        voxels[i][j][k].empty();
                         continue;
                     }
 
+                    // sampled voxel, post-processing required
                     Voxel voxel = voxels[i][j][k];
 
                     // mean angle
@@ -941,13 +944,13 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
                 }
             }
         }
-        
+
         if (nFallback > 0) {
             StringBuilder sb = new StringBuilder();
             float nVoxel = parameters.infos.getSplit().x * parameters.infos.getSplit().y * parameters.infos.getSplit().z;
             float fraction = 100.f * nFallback / nVoxel;
             sb.append("Transmittance computation switched to fallback mode (lower precision) for ")
-                    .append(nFallback).append("/").append((int)nVoxel).append(" voxels")
+                    .append(nFallback).append("/").append((int) nVoxel).append(" voxels")
                     .append(" (~").append(String.format("%.1f", fraction)).append("%)");
             LOGGER.warn(sb.toString());
         }
@@ -1055,8 +1058,6 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
         voxels = new Voxel[parameters.infos.getSplit().x][parameters.infos.getSplit().y][parameters.infos.getSplit().z];
 
         if (groundEnergyEnabled) {
-            // allocate
-            //LOGGER.info("allocate!!!!!!!!");
             groundEnergy = new GroundEnergy[parameters.infos.getSplit().x][parameters.infos.getSplit().y];
             for (int i = 0; i < parameters.infos.getSplit().x; i++) {
                 for (int j = 0; j < parameters.infos.getSplit().y; j++) {
@@ -1065,22 +1066,13 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
             }
         }
 
+        // main voxel space
         Scene scene = new Scene();
         scene.setBoundingBox(new BoundingBox3d(parameters.infos.getMinCorner(), parameters.infos.getMaxCorner()));
-
         voxelManager = new VoxelManager(scene, new VoxelManagerSettings(parameters.infos.getSplit(), VoxelManagerSettings.NON_TORIC_FINITE_BOX_TOPOLOGY));
-
+        // print information on main voxel space
         LOGGER.info(voxelManager.getInformations());
 
-        // initialize voxel
-        for (int i = 0; i < parameters.infos.getSplit().x; i++) {
-            for (int j = 0; j < parameters.infos.getSplit().y; j++) {
-                for (int k = 0; k < parameters.infos.getSplit().z; k++) {
-                    voxels[i][j][k] = initVoxel(i, j, k);
-                }
-            }
-        }
-
         // sub voxel space
         if (subSamplingEnabled) {
             Scene subScene = new Scene();
@@ -1121,7 +1113,14 @@ public class Voxelization extends fr.amap.commons.util.Process implements Cancel
     }
 
     public Voxel getVoxel(int i, int j, int k) {
-        return voxels[i][j][k];
+
+        if (null != voxels[i][j][k]) {
+            return voxels[i][j][k];
+        } else {
+            Voxel voxel = new Voxel(i, j, k);
+            voxel.empty();
+            return voxel;
+        }
     }
 
     public int getNbShotsProcessed() {