fix(Glyph3DMapper): use correct shift-scale transform

Author: jadh4v

Sources/Rendering/OpenGL/CellArrayBufferObject/helpers.js

@@ -1,3 +1,5 @@
+import { mat4, quat, vec3 } from 'gl-matrix';
+
 export function computeCoordShiftAndScale(points) {
   // Find out if shift scale should be used
   // Compute squares of diagonal size and distance from the origin
@@ -41,4 +43,19 @@ export function computeCoordShiftAndScale(points) {
   };
 }
 
-export default { computeCoordShiftAndScale };
+export function computeInverseShiftAndScaleMatrix(coordShift, coordScale) {
+  const inverseScale = new Float64Array(3);
+  vec3.inverse(inverseScale, coordScale);
+
+  const matrix = new Float64Array(16);
+  mat4.fromRotationTranslationScale(
+    matrix,
+    quat.create(),
+    coordShift,
+    inverseScale
+  );
+
+  return matrix;
+}
+
+export default { computeCoordShiftAndScale, computeInverseShiftAndScaleMatrix };

Sources/Rendering/OpenGL/CellArrayBufferObject/index.js

@@ -1,32 +1,20 @@
-import { mat4, quat, vec3 } from 'gl-matrix';
+import { vec3 } from 'gl-matrix';
 
 import macro from 'vtk.js/Sources/macros';
 import vtkBufferObject from 'vtk.js/Sources/Rendering/OpenGL/BufferObject';
 import { ObjectType } from 'vtk.js/Sources/Rendering/OpenGL/BufferObject/Constants';
 import { Representation } from 'vtk.js/Sources/Rendering/Core/Property/Constants';
-import { computeCoordShiftAndScale } from 'vtk.js/Sources/Rendering/OpenGL/CellArrayBufferObject/helpers';
+import {
+  computeCoordShiftAndScale,
+  computeInverseShiftAndScaleMatrix,
+} from 'vtk.js/Sources/Rendering/OpenGL/CellArrayBufferObject/helpers';
 
 const { vtkErrorMacro } = macro;
 
 // ----------------------------------------------------------------------------
 // Static functions
 // ----------------------------------------------------------------------------
 
-function computeInverseShiftAndScaleMatrix(coordShift, coordScale) {
-  const inverseScale = new Float64Array(3);
-  vec3.inverse(inverseScale, coordScale);
-
-  const matrix = new Float64Array(16);
-  mat4.fromRotationTranslationScale(
-    matrix,
-    quat.create(),
-    coordShift,
-    inverseScale
-  );
-
-  return matrix;
-}
-
 function shouldApplyCoordShiftAndScale(coordShift, coordScale) {
   if (coordShift === null || coordScale === null) {
     return false;

Sources/Rendering/OpenGL/Glyph3DMapper/index.js

@@ -7,7 +7,10 @@ import vtkHardwareSelector from 'vtk.js/Sources/Rendering/OpenGL/HardwareSelecto
 import vtkProperty from 'vtk.js/Sources/Rendering/Core/Property';
 import vtkOpenGLPolyDataMapper from 'vtk.js/Sources/Rendering/OpenGL/PolyDataMapper';
 import vtkShaderProgram from 'vtk.js/Sources/Rendering/OpenGL/ShaderProgram';
-import { computeCoordShiftAndScale } from 'vtk.js/Sources/Rendering/OpenGL/CellArrayBufferObject/helpers';
+import {
+  computeCoordShiftAndScale,
+  computeInverseShiftAndScaleMatrix,
+} from 'vtk.js/Sources/Rendering/OpenGL/CellArrayBufferObject/helpers';
 
 import { registerOverride } from 'vtk.js/Sources/Rendering/OpenGL/ViewNodeFactory';
 import { primTypes } from '../Helper';
@@ -23,16 +26,6 @@ const EndEvent = { type: 'EndEvent' };
 const MAT4_BYTE_SIZE = 64;
 const MAT4_ELEMENT_COUNT = 16;
 
-function applyShiftScaleToMat(mat, shift, scale) {
-  // the translation component of a 4x4 column-major matrix
-  mat[12] = (mat[12] - shift[0]) * scale[0];
-  mat[13] = (mat[13] - shift[1]) * scale[1];
-  mat[14] = (mat[14] - shift[2]) * scale[2];
-  mat[0] *= scale[0];
-  mat[5] *= scale[1];
-  mat[10] *= scale[2];
-}
-
 // ----------------------------------------------------------------------------
 // vtkOpenGLSphereMapper methods
 // ----------------------------------------------------------------------------
@@ -714,13 +707,18 @@ function vtkOpenGLGlyph3DMapper(publicAPI, model) {
 
       if (useShiftAndScale) {
         const buf = garray.buffer;
+        const shiftScaleMat = computeInverseShiftAndScaleMatrix(
+          coordShift,
+          coordScale
+        );
+        mat4.invert(shiftScaleMat, shiftScaleMat);
         for (
           let ptIdx = 0;
           ptIdx < garray.byteLength;
           ptIdx += MAT4_BYTE_SIZE
         ) {
           const mat = new Float32Array(buf, ptIdx, MAT4_ELEMENT_COUNT);
-          applyShiftScaleToMat(mat, coordShift, coordScale);
+          mat4.multiply(mat, shiftScaleMat, mat);
         }
       }