Support unquantized vertex tables (#3288)

* Remove obsolete unused BingElevation-based terrain.

* MeshPointList

* Option to quantize positions.

* Simplify graphic args pt 1: delete MeshGraphicArgs.

* Get stuff (mostly tests) compiling.

* Clean up (to an extent) MeshArgs and PolylineArgs. Tests are annoying.

* remove obsolete TODO.

* Quantized vertex table builders.

* unquantized vertex table builders.

* Mesh/PolylineArgs.points doesn't need an add method.

* Vertex comparison tolerance based on quantization params or chord tolerance.

* fix dumb test.

* fix a couple tests.

* fix vertex comparison.

* Clarify feature index is 24 bits and material index is not produced by frontend code.

* indentation

* ShaderBuilderFlags is an object.

We will need max rgba per vertex shortly.

* Read vertex table data up front.

* Use pre-sampled data for position.

* Use pre-sampled data for normals and color index.

* Use pre-sampled vertex data everywhere.

* Support decoding unquantized vertex position.

* Point3dList.range; qparams can be used for deriving range even if positions are not quantized.

* Flag specifying whether positions are quantized.

* consolidate normal computation.

* When reading vertex data conditionalize based on whether positions are quantized.

* Decode unquantized polyline/edge endpoints.

* PolylineTesselator.

* Turn on unquantized positions for decorations.

Test failures ensue.

* fix 3 tests.

the rest of the failures are from rendering.

* Test for unquantized vertex table (failing).

* Get test passing.

* unquantized geometry now renders correctly.

* update TODO. Probably won't address.

* Define unquantized positions relative to center of range.

* Update test.

* extract-api

* lint....

* please build my code.

Author: pmconne

common/api/core-frontend.api.md

@@ -1617,8 +1617,6 @@ export class BingElevationProvider {
     constructor();
     // @internal (undocumented)
     getGeodeticToSeaLevelOffset(point: Point3d, iModel: IModelConnection): Promise<number>;
-    // @internal (undocumented)
-    getGraphic(latLongRange: Range2d, corners: Point3d[], groundBias: number, texture: RenderTexture, system: RenderSystem): Promise<RenderGraphic | undefined>;
     getHeight(carto: Cartographic, geodetic?: boolean): Promise<any>;
     getHeightAverage(iModel: IModelConnection): Promise<number>;
     getHeightRange(iModel: IModelConnection): Promise<Range1d>;

common/changes/@itwin/core-frontend/floating-point-decorations_2022-03-03-21-24.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@itwin/core-frontend",
+      "comment": "Increase precision for vertex positions when producing decoration graphics, to reduce visual artifacts.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@itwin/core-frontend"
+}

core/frontend/src/render/ParticleCollectionBuilder.ts

@@ -9,7 +9,7 @@
 import { Id64String } from "@itwin/core-bentley";
 import { Matrix3d, Point2d, Point3d, Range3d, Transform, Vector2d, XAndY, XYAndZ } from "@itwin/core-geometry";
 import {
-  ColorDef, Feature, FeatureTable, PackedFeatureTable, QParams3d, QPoint3dList, RenderTexture,
+  ColorDef, ColorIndex, Feature, FeatureIndex, FeatureTable, FillFlags, PackedFeatureTable, QParams3d, QPoint3dList, RenderTexture,
 } from "@itwin/core-common";
 import { Viewport } from "../Viewport";
 import { RenderGraphic } from "./RenderGraphic";
@@ -343,19 +343,29 @@ function createQuad(size: XAndY, texture: RenderTexture, transparency: number):
     new Point3d(-halfWidth, halfHeight, 0), new Point3d(halfWidth, halfHeight, 0),
   ];
 
-  const quadArgs = new MeshArgs();
   const range = new Range3d();
   range.low = corners[0];
   range.high = corners[3];
-  quadArgs.points = new QPoint3dList(QParams3d.fromRange(range));
-  for (const corner of corners)
-    quadArgs.points.add(corner);
 
-  quadArgs.vertIndices = [0, 1, 2, 2, 1, 3];
-  quadArgs.textureUv = [new Point2d(0, 1), new Point2d(1, 1), new Point2d(0, 0), new Point2d(1, 0)];
-  quadArgs.texture = texture;
-  quadArgs.colors.initUniform(ColorDef.white.withTransparency(transparency));
-  quadArgs.isPlanar = true;
+  const points = new QPoint3dList(QParams3d.fromRange(range));
+  for (const corner of corners)
+    points.add(corner);
+
+  const colors = new ColorIndex();
+  colors.initUniform(ColorDef.white.withTransparency(transparency));
+
+  const quadArgs: MeshArgs = {
+    points,
+    vertIndices: [0, 1, 2, 2, 1, 3],
+    fillFlags: FillFlags.None,
+    isPlanar: true,
+    colors,
+    features: new FeatureIndex(),
+    textureMapping: {
+      texture,
+      uvParams: [new Point2d(0, 1), new Point2d(1, 1), new Point2d(0, 0), new Point2d(1, 0)],
+    },
+  };
 
   return MeshParams.create(quadArgs);
 }

core/frontend/src/render/RenderSystem.ts

@@ -8,7 +8,7 @@
 
 import { base64StringToUint8Array, Id64String, IDisposable } from "@itwin/core-bentley";
 import {
-  ColorDef, ElementAlignedBox3d, FeatureIndexType, Frustum, Gradient, ImageBuffer, ImageBufferFormat, ImageSource, ImageSourceFormat,
+  ColorDef, ColorIndex, ElementAlignedBox3d, FeatureIndex, FeatureIndexType, FillFlags, Frustum, Gradient, ImageBuffer, ImageBufferFormat, ImageSource, ImageSourceFormat,
   isValidImageSourceFormat, PackedFeatureTable, QParams3d, QPoint3dList, RenderMaterial, RenderTexture, SkyGradient, TextureProps, TextureTransparency,
 } from "@itwin/core-common";
 import { ClipVector, Matrix3d, Point2d, Point3d, Range2d, Range3d, Transform, Vector2d, XAndY } from "@itwin/core-geometry";
@@ -441,39 +441,40 @@ export abstract class RenderSystem implements IDisposable {
   public createBackgroundMapDrape(_drapedTree: TileTreeReference, _mapTree: MapTileTreeReference): RenderTextureDrape | undefined { return undefined; }
   /** @internal */
   public createTile(tileTexture: RenderTexture, corners: Point3d[], featureIndex?: number): RenderGraphic | undefined {
-    const rasterTile = new MeshArgs();
-
     // corners
     // [0] [1]
     // [2] [3]
     // Quantize the points according to their range
-    rasterTile.points = new QPoint3dList(QParams3d.fromRange(Range3d.create(...corners)));
-    for (let i = 0; i < 4; ++i)
-      rasterTile.points.add(corners[i]);
+    const points = new QPoint3dList(QParams3d.fromRange(Range3d.create(...corners)));
+    for (let i = 0; i < 4; i++)
+      points.add(corners[i]);
 
     // Now remove the translation from the quantized points and put it into a transform instead.
     // This prevents graphical artifacts when quantization origin is large relative to quantization scale.
     // ###TODO: Would be better not to create a branch for every tile.
-    const qorigin = rasterTile.points.params.origin;
+    const qorigin = points.params.origin;
     const transform = Transform.createTranslationXYZ(qorigin.x, qorigin.y, qorigin.z);
     qorigin.setZero();
 
-    rasterTile.vertIndices = [0, 1, 2, 2, 1, 3];
-    rasterTile.textureUv = [
-      new Point2d(0.0, 0.0),
-      new Point2d(1.0, 0.0),
-      new Point2d(0.0, 1.0),
-      new Point2d(1.0, 1.0),
-    ];
-
-    rasterTile.texture = tileTexture;
-    rasterTile.isPlanar = true;
-
+    const features = new FeatureIndex();
     if (undefined !== featureIndex) {
-      rasterTile.features.featureID = featureIndex;
-      rasterTile.features.type = FeatureIndexType.Uniform;
+      features.featureID = featureIndex;
+      features.type = FeatureIndexType.Uniform;
     }
 
+    const rasterTile: MeshArgs = {
+      points,
+      vertIndices: [0, 1, 2, 2, 1, 3],
+      isPlanar: true,
+      features,
+      colors: new ColorIndex(),
+      fillFlags: FillFlags.None,
+      textureMapping: {
+        uvParams: [new Point2d(0, 0), new Point2d(1, 0), new Point2d(0, 1), new Point2d(1, 1)],
+        texture: tileTexture,
+      },
+    };
+
     const trimesh = this.createTriMesh(rasterTile);
     if (undefined === trimesh)
       return undefined;

core/frontend/src/render/primitives/EdgeParams.ts

@@ -293,7 +293,10 @@ export interface EdgeParams {
 export namespace EdgeParams {
   export function fromMeshArgs(meshArgs: MeshArgs, maxWidth?: number): EdgeParams | undefined {
     const args = meshArgs.edges;
-    const doJoints = wantJointTriangles(args.width, meshArgs.is2d);
+    if (!args)
+      return undefined;
+
+    const doJoints = wantJointTriangles(args.width, true === meshArgs.is2d);
     const polylines = doJoints ? TesselatedPolyline.fromMesh(meshArgs) : undefined;
 
     let segments: SegmentEdgeParams | undefined;

core/frontend/src/render/primitives/PolylineParams.ts

@@ -87,7 +87,6 @@ class PolylineVertex {
 
 class PolylineTesselator {
   private _polylines: PolylineData[];
-  private _points: QPoint3dList;
   private _doJoints: boolean;
   private _numIndices = 0;
   private _vertIndex: number[] = [];
@@ -96,9 +95,15 @@ class PolylineTesselator {
   private _nextParam: number[] = [];
   private _position: Point3d[] = [];
 
-  public constructor(polylines: PolylineData[], points: QPoint3dList, doJointTriangles: boolean) {
+  public constructor(polylines: PolylineData[], points: QPoint3dList | Point3d[], doJointTriangles: boolean) {
     this._polylines = polylines;
-    this._points = points;
+    if (points instanceof QPoint3dList) {
+      for (const p of points.list)
+        this._position.push(p.unquantize(points.params));
+    } else {
+      this._position = points;
+    }
+
     this._doJoints = doJointTriangles;
   }
 
@@ -107,16 +112,13 @@ class PolylineTesselator {
   }
 
   public static fromMesh(args: MeshArgs): PolylineTesselator | undefined {
-    if (undefined !== args.edges.polylines.lines && undefined !== args.points)
-      return new PolylineTesselator(args.edges.polylines.lines, args.points, wantJointTriangles(args.edges.width, args.is2d));
+    if (undefined !== args.edges?.polylines.lines && undefined !== args.points)
+      return new PolylineTesselator(args.edges.polylines.lines, args.points, wantJointTriangles(args.edges.width, true === args.is2d));
 
     return undefined;
   }
 
   public tesselate(): TesselatedPolyline {
-    for (const p of this._points.list)
-      this._position.push(p.unquantize(this._points.params));
-
     this._tesselate();
 
     const vertIndex = VertexIndices.fromArray(this._vertIndex);

core/frontend/src/render/primitives/VertexKey.ts

@@ -7,25 +7,36 @@
  */
 
 import { assert, compareWithTolerance, IndexMap } from "@itwin/core-bentley";
-import { Point2d } from "@itwin/core-geometry";
-import { OctEncodedNormal, QPoint3d } from "@itwin/core-common";
+import { Point2d, Point3d, XYAndZ } from "@itwin/core-geometry";
+import { OctEncodedNormal } from "@itwin/core-common";
 
 /** @internal */
 export interface VertexKeyProps {
-  position: QPoint3d;
+  position: Point3d;
   fillColor: number;
   normal?: OctEncodedNormal;
   uvParam?: Point2d;
 }
 
+function comparePositions(p0: Point3d, p1: Point3d, tolerance: XYAndZ): number {
+  let diff = compareWithTolerance(p0.x, p1.x, tolerance.x);
+  if (0 === diff) {
+    diff = compareWithTolerance(p0.y, p1.y, tolerance.y);
+    if (0 === diff)
+      diff = compareWithTolerance(p0.z, p1.z, tolerance.z);
+  }
+
+  return diff;
+}
+
 /** @internal */
 export class VertexKey {
-  public readonly position: QPoint3d;
+  public readonly position: Point3d;
   public readonly normal?: OctEncodedNormal;
   public readonly uvParam?: Point2d;
   public readonly fillColor: number;
 
-  public constructor(position: QPoint3d, fillColor: number, normal?: OctEncodedNormal, uvParam?: Point2d) {
+  public constructor(position: Point3d, fillColor: number, normal?: OctEncodedNormal, uvParam?: Point2d) {
     this.position = position.clone();
     this.fillColor = fillColor;
     this.normal = normal;
@@ -34,7 +45,7 @@ export class VertexKey {
 
   public static create(props: VertexKeyProps): VertexKey { return new VertexKey(props.position, props.fillColor, props.normal, props.uvParam); }
 
-  public equals(rhs: VertexKey): boolean {
+  public equals(rhs: VertexKey, tolerance: XYAndZ): boolean {
     if (this.fillColor !== rhs.fillColor)
       return false;
 
@@ -44,24 +55,24 @@ export class VertexKey {
         return false;
     }
 
-    if (!this.position.equals(rhs.position))
+    if (0 !== comparePositions(this.position, rhs.position, tolerance))
       return false;
 
     if (undefined !== this.uvParam) {
       assert(undefined !== rhs.uvParam);
-      return this.uvParam.isAlmostEqual(rhs.uvParam, 0.1);
+      return this.uvParam.isAlmostEqual(rhs.uvParam, 0.1); // ###TODO surely this is a typo?
     }
 
     return true;
   }
 
-  public compare(rhs: VertexKey): number {
+  public compare(rhs: VertexKey, tolerance: XYAndZ): number {
     if (this === rhs)
       return 0;
 
     let diff = this.fillColor - rhs.fillColor;
     if (0 === diff) {
-      diff = this.position.compare(rhs.position);
+      diff = comparePositions(this.position, rhs.position, tolerance);
       if (0 === diff) {
         if (undefined !== this.normal) {
           assert(undefined !== rhs.normal);
@@ -83,9 +94,22 @@ export class VertexKey {
 
 /** @internal */
 export class VertexMap extends IndexMap<VertexKey> {
-  public constructor() { super((lhs, rhs) => lhs.compare(rhs)); }
+  private readonly _tolerance: XYAndZ;
+
+  public constructor(tolerance: XYAndZ) {
+    super((lhs, rhs) => lhs.compare(rhs, tolerance));
+    this._tolerance = tolerance;
+  }
 
   public insertKey(props: VertexKeyProps, onInsert?: (vk: VertexKey) => any): number {
     return this.insert(VertexKey.create(props), onInsert);
   }
+
+  public arePositionsAlmostEqual(p0: VertexKeyProps, p1: VertexKeyProps): boolean {
+    return 0 === this.comparePositions(p0, p1);
+  }
+
+  public comparePositions(p0: VertexKeyProps, p1: VertexKeyProps): number {
+    return comparePositions(p0.position, p1.position, this._tolerance);
+  }
 }