feat(camera): added a new model transform matrix to the Camera API

The new model transform matrix can be used for transformations like scale, shear, rotations and
translations.

Author: sankhesh

Sources/Rendering/Core/Camera/index.js

@@ -498,6 +498,12 @@ function vtkCamera(publicAPI, model) {
     publicAPI.computeViewParametersFromViewMatrix(tmpMatrix);
   };
 
+  publicAPI.setModelTransformMatrix = (mat) => {
+    model.modelTransformMatrix = mat;
+  };
+
+  publicAPI.getModelTransformMatrix = () => model.modelTransformMatrix;
+
   publicAPI.setViewMatrix = (mat) => {
     model.viewMatrix = mat;
     if (model.viewMatrix) {
@@ -509,6 +515,10 @@ function vtkCamera(publicAPI, model) {
 
   publicAPI.getViewMatrix = () => {
     if (model.viewMatrix) {
+      if (model.modelTransformMatrix) {
+        mat4.multiply(tmpMatrix, model.viewMatrix, model.modelTransformMatrix);
+        return tmpMatrix;
+      }
       return model.viewMatrix;
     }
 
@@ -522,7 +532,11 @@ function vtkCamera(publicAPI, model) {
     mat4.transpose(tmpMatrix, tmpMatrix);
 
     const result = new Float64Array(16);
-    mat4.copy(result, tmpMatrix);
+    if (model.modelTransformMatrix) {
+      mat4.multiply(result, tmpMatrix, model.modelTransformMatrix);
+    } else {
+      mat4.copy(result, tmpMatrix);
+    }
     return result;
   };
 
@@ -767,6 +781,7 @@ export const DEFAULT_VALUES = {
   freezeFocalPoint: false,
   projectionMatrix: null,
   viewMatrix: null,
+  modelTransformMatrix: null,
   cameraLightTransform: mat4.create(),
 
   // used for world to physical transformations