* feat: 🎸 Progressive volume loading for vtk viewport (#1055)

* feat: 🎸 Progressive volume loading for vtk viewport

Adds progressive volume loading for vtkjs viewport whilst the frames are
streamed from PACs and rebuilt in the volume.

Closes: closes #1051

* Update to react-vtkjs-viewport 0.3.0

extensions/vtk/src/utils/setMPRLayout.js

@@ -1,11 +1,23 @@
 import setLayoutAndViewportData from './setLayoutAndViewportData.js';
 
-export default function setMPRLayout(displaySet) {
+export default function setMPRLayout(
+  displaySet,
+  viewportPropsArray,
+  numRows = 1,
+  numColumns = 3
+) {
   return new Promise((resolve, reject) => {
     const viewports = [];
-    const numRows = 1;
-    const numColumns = 3;
     const numViewports = numRows * numColumns;
+
+    if (viewportPropsArray && viewportPropsArray.length !== numViewports) {
+      reject(
+        new Error(
+          'viewportProps is supplied but its length is not equal to numViewports'
+        )
+      );
+    }
+
     const viewportSpecificData = {};
 
     for (let i = 0; i < numViewports; i++) {
@@ -17,8 +29,8 @@ export default function setMPRLayout(displaySet) {
     const apis = [];
     viewports.forEach((viewport, index) => {
       apis[index] = null;
+      const viewportProps = viewportPropsArray[index];
       viewports[index] = Object.assign({}, viewports[index], {
-        // plugin: 'vtk',
         vtk: {
           mode: 'mpr', // TODO: not used
           afterCreation: api => {
@@ -28,6 +40,7 @@ export default function setMPRLayout(displaySet) {
               resolve(apis);
             }
           },
+          ...viewportProps,
         },
       });
     });