Merge pull request #12681 from CesiumGS/voxel-cylinder-step

Fix step size for cylinder voxels

Author: jjspace

Apps/Sandcastle/gallery/Voxel Picking.html

@@ -75,6 +75,8 @@
         function ProceduralMultiTileVoxelProvider(shape) {
           this.shape = shape;
           this.dimensions = new Cesium.Cartesian3(4, 4, 4);
+          this.minBounds = Cesium.VoxelShapeType.getMinBounds(shape).clone();
+          this.maxBounds = Cesium.VoxelShapeType.getMaxBounds(shape).clone();
           this.names = ["color"];
           this.types = [Cesium.MetadataType.VEC4];
           this.componentTypes = [Cesium.MetadataComponentType.FLOAT32];
@@ -134,11 +136,9 @@
           return dataColor;
         }
 
-        const provider = new ProceduralMultiTileVoxelProvider(Cesium.VoxelShapeType.BOX);
-
         const customShader = new Cesium.CustomShader({
           fragmentShaderText: `void fragmentMain(FragmentInput fsInput, inout czm_modelMaterial material)
-    {
+  {
       vec3 voxelNormal = fsInput.attributes.normalEC;
       float diffuse = max(0.0, dot(voxelNormal, czm_lightDirectionEC));
       float lighting = 0.5 + 0.5 * diffuse;
@@ -147,13 +147,13 @@
       int sampleIndex = fsInput.voxel.sampleIndex;
       vec3 cellColor = fsInput.metadata.color.rgb * lighting;
       if (tileIndex == u_selectedTile && sampleIndex == u_selectedSample) {
-        material.diffuse = mix(cellColor, vec3(1.0), 0.5);
-        material.alpha = fsInput.metadata.color.a;
+          material.diffuse = mix(cellColor, vec3(1.0), 0.5);
+          material.alpha = fsInput.metadata.color.a;
       } else {
-        material.diffuse = cellColor;
-        material.alpha = fsInput.metadata.color.a;
+          material.diffuse = cellColor;
+          material.alpha = fsInput.metadata.color.a;
       }
-    }`,
+  }`,
           uniforms: {
             u_selectedTile: {
               type: Cesium.UniformType.INT,
@@ -166,18 +166,54 @@
           },
         });
 
-        const voxelPrimitive = scene.primitives.add(
-          new Cesium.VoxelPrimitive({
+        function createPrimitive(provider) {
+          viewer.scene.primitives.removeAll();
+
+          const voxelPrimitive = new Cesium.VoxelPrimitive({
             provider: provider,
             customShader: customShader,
-          }),
-        );
+          });
+          voxelPrimitive.nearestSampling = true;
 
-        voxelPrimitive.nearestSampling = true;
+          viewer.scene.primitives.add(voxelPrimitive);
+          camera.flyToBoundingSphere(voxelPrimitive.boundingSphere, {
+            duration: 0.0,
+          });
 
-        camera.flyToBoundingSphere(voxelPrimitive.boundingSphere, {
-          duration: 0.0,
-        });
+          return voxelPrimitive;
+        }
+
+        Sandcastle.addToolbarMenu([
+          {
+            text: "Box - Procedural Tileset",
+            onselect: function () {
+              const provider = new ProceduralMultiTileVoxelProvider(
+                Cesium.VoxelShapeType.BOX,
+              );
+              const primitive = createPrimitive(provider);
+            },
+          },
+          {
+            text: "Ellipsoid - Procedural Tileset",
+            onselect: function () {
+              const provider = new ProceduralMultiTileVoxelProvider(
+                Cesium.VoxelShapeType.ELLIPSOID,
+              );
+              provider.minBounds.z = 0.0;
+              provider.maxBounds.z = 1000000.0;
+              const primitive = createPrimitive(provider);
+            },
+          },
+          {
+            text: "Cylinder - Procedural Tileset",
+            onselect: function () {
+              const provider = new ProceduralMultiTileVoxelProvider(
+                Cesium.VoxelShapeType.CYLINDER,
+              );
+              const primitive = createPrimitive(provider);
+            },
+          },
+        ]);
 
         const handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
         const pickedCoordinate = document.getElementById("pickedCoordinate");

CHANGES.md

@@ -7,6 +7,7 @@
 ### Fixes :wrench:
 
 - Updates use of deprecated options on createImageBitmap. [#12664](https://github.com/CesiumGS/cesium/pull/12664)
+- Fixed raymarching step size for cylindrical voxels. [#12681](https://github.com/CesiumGS/cesium/pull/12681)
 
 #### Additions :tada:
 

packages/engine/Source/Shaders/Voxels/convertUvToCylinder.glsl

@@ -38,7 +38,7 @@ PointJacobianT convertUvToShapeSpaceDerivative(in vec3 positionUv) {
     vec3 east = normalize(vec3(-position.y, position.x, 0.0));
 
     vec3 point = vec3(radius, angle, height);
-    mat3 jacobianT = mat3(radial, z, east / length(position.xy));
+    mat3 jacobianT = mat3(radial, east / length(position.xy), z);
     return PointJacobianT(point, jacobianT);
 }