feat(VolumeMapper): Add forceNearestInterpolation

Kitware · Mar 20, 2024 · 7317248 · 7317248
1 parent c7ba534
commit 7317248
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Showing 6 changed files with 114 additions and 39 deletions.
diff --git a/Sources/Rendering/Core/VolumeMapper/example/controller.html b/Sources/Rendering/Core/VolumeMapper/example/controller.html
@@ -10,4 +10,5 @@
   </fieldset>
   <select id='volume' style="margin: 5px;"></select>
   <select id='preset' style="margin: 5px; display: none;"></select>
+  <div id="forceNearest"></div>
 </form>
diff --git a/Sources/Rendering/Core/VolumeMapper/example/index.js b/Sources/Rendering/Core/VolumeMapper/example/index.js
@@ -49,6 +49,7 @@ const reader = vtkHttpDataSetReader.newInstance({ fetchGzip: true });
 const volumeOptions = {};
 const volumeSelectElem = document.getElementById('volume');
 const presetSelectElem = document.getElementById('preset');
+const forceNearestElem = document.getElementById('forceNearest');
 
 const actor = vtkVolume.newInstance();
 const mapper = vtkVolumeMapper.newInstance();
@@ -144,6 +145,14 @@ if (light.getPositional()) {
   renderer.addActor(lca);
 }
 
+{
+  const optionElem = document.createElement('option');
+  optionElem.label = 'Default';
+  optionElem.value = '';
+  presetSelectElem.appendChild(optionElem);
+  presetSelectElem.value = optionElem.value;
+}
+
 Object.keys(ColorMixPreset).forEach((key) => {
   if (key === 'CUSTOM') {
     // Don't enable custom mode
@@ -157,20 +166,32 @@ Object.keys(ColorMixPreset).forEach((key) => {
   presetSelectElem.appendChild(optionElem);
 });
 
-{
-  const optionElem = document.createElement('option');
-  optionElem.label = 'Default';
-  optionElem.value = '';
-  presetSelectElem.appendChild(optionElem);
-  presetSelectElem.value = optionElem.value;
-}
-
 const setColorMixPreset = (presetKey) => {
   const preset = presetKey ? ColorMixPreset[presetKey] : null;
   actor.getProperty().setColorMixPreset(preset);
   presetSelectElem.value = presetKey;
 };
 
+function updateForceNearestElem(comp) {
+  forceNearestElem.replaceChildren();
+  for (let c = 0; c < comp; ++c) {
+    const checkboxElem = document.createElement('input');
+    checkboxElem.type = 'checkbox';
+    checkboxElem.checked = actor.getProperty().getForceNearestInterpolation(c);
+    checkboxElem.addEventListener('change', () => {
+      actor.getProperty().setForceNearestInterpolation(c, checkboxElem.checked);
+      renderWindow.render();
+    });
+    forceNearestElem.appendChild(checkboxElem);
+    const labelElem = document.createElement('label');
+    labelElem.innerText = `Force linear interpolation for component ${c}`;
+    forceNearestElem.appendChild(labelElem);
+    forceNearestElem.appendChild(document.createElement('br'));
+  }
+}
+
+updateForceNearestElem(1);
+
 volumeSelectElem.addEventListener('change', () => {
   const { comp, data } = volumeOptions[volumeSelectElem.value];
   if (comp === 1) {
@@ -179,6 +200,7 @@ volumeSelectElem.addEventListener('change', () => {
   } else {
     presetSelectElem.style.display = 'block';
   }
+  updateForceNearestElem(comp);
   const array = mapper.getInputData().getPointData().getArray(0);
   array.setData(data);
   array.setNumberOfComponents(comp);

diff --git a/Sources/Rendering/Core/VolumeProperty/index.d.ts b/Sources/Rendering/Core/VolumeProperty/index.d.ts
@@ -135,6 +135,12 @@ export interface vtkVolumeProperty extends vtkObject {
 	 */
 	getUseGradientOpacity(index: number): boolean;
 
+	/**
+	 * @see setForceNearestInterpolation
+	 * @param {Number} index
+	 */
+	getForceNearestInterpolation(index: number): boolean;
+
 	/**
 	 *
 	 */
@@ -315,6 +321,15 @@ export interface vtkVolumeProperty extends vtkObject {
 	 */
 	setComponentWeight(index: number, value: number): boolean;
 
+	/**
+	 * Force the nearest neighbor interpolation of one or more of the components
+	 * The interpolation for the rest of the volume is set using `setInterpolationType`
+	 * @see setInterpolationType
+	 * @param {Number} index
+	 * @param {Boolean} value
+	 */
+	setForceNearestInterpolation(index: number, value: boolean): boolean;
+
 	/**
 	 * Get the scalar component weights.
 	 * @param {Number} index 

diff --git a/Sources/Rendering/Core/VolumeProperty/index.js b/Sources/Rendering/Core/VolumeProperty/index.js
@@ -211,6 +211,7 @@ function vtkVolumeProperty(publicAPI, model) {
     'gradientOpacityMaximumValue',
     'gradientOpacityMaximumOpacity',
     'opacityMode',
+    'forceNearestInterpolation',
   ];
   sets.forEach((val) => {
     const cap = macro.capitalize(val);
@@ -232,6 +233,7 @@ function vtkVolumeProperty(publicAPI, model) {
     'gradientOpacityMaximumValue',
     'gradientOpacityMaximumOpacity',
     'opacityMode',
+    'forceNearestInterpolation',
   ];
   gets.forEach((val) => {
     const cap = macro.capitalize(val);
@@ -283,6 +285,7 @@ export function extend(publicAPI, model, initialValues = {}) {
         useGradientOpacity: false,
 
         componentWeight: 1.0,
+        forceNearestInterpolation: false,
       });
     }
   }

diff --git a/Sources/Rendering/OpenGL/VolumeMapper/index.js b/Sources/Rendering/OpenGL/VolumeMapper/index.js
@@ -190,10 +190,11 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
   };
 
   publicAPI.replaceShaderValues = (shaders, ren, actor) => {
+    const actorProps = actor.getProperty();
     let FSSource = shaders.Fragment;
 
     // define some values in the shader
-    const iType = actor.getProperty().getInterpolationType();
+    const iType = actorProps.getInterpolationType();
     if (iType === InterpolationType.LINEAR) {
       FSSource = vtkShaderProgram.substitute(
         FSSource,
@@ -202,7 +203,7 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
       ).result;
     }
 
-    const vtkImageLabelOutline = actor.getProperty().getUseLabelOutline();
+    const vtkImageLabelOutline = actorProps.getUseLabelOutline();
     if (vtkImageLabelOutline === true) {
       FSSource = vtkShaderProgram.substitute(
         FSSource,
@@ -225,27 +226,33 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
         '//VTK::IndependentComponentsOn',
         '#define UseIndependentComponents'
       ).result;
+    }
 
-      // Define any proportional components
-      const proportionalComponents = [];
-      for (let nc = 0; nc < numComp; nc++) {
-        if (
-          actor.getProperty().getOpacityMode(nc) === OpacityMode.PROPORTIONAL
-        ) {
-          proportionalComponents.push(`#define vtkComponent${nc}Proportional`);
-        }
+    // Define any proportional components
+    const proportionalComponents = [];
+    const forceNearestComponents = [];
+    for (let nc = 0; nc < numComp; nc++) {
+      if (actorProps.getOpacityMode(nc) === OpacityMode.PROPORTIONAL) {
+        proportionalComponents.push(`#define vtkComponent${nc}Proportional`);
       }
-
-      if (proportionalComponents.length > 0) {
-        FSSource = vtkShaderProgram.substitute(
-          FSSource,
-          '//VTK::vtkProportionalComponents',
-          proportionalComponents.join('\n')
-        ).result;
+      if (actorProps.getForceNearestInterpolation(nc)) {
+        forceNearestComponents.push(`#define vtkComponent${nc}ForceNearest`);
       }
     }
 
-    const colorMixPreset = actor.getProperty().getColorMixPreset();
+    FSSource = vtkShaderProgram.substitute(
+      FSSource,
+      '//VTK::vtkProportionalComponents',
+      proportionalComponents.join('\n')
+    ).result;
+
+    FSSource = vtkShaderProgram.substitute(
+      FSSource,
+      '//VTK::vtkForceNearestComponents',
+      forceNearestComponents.join('\n')
+    ).result;
+
+    const colorMixPreset = actorProps.getColorMixPreset();
     const colorMixCode = getColorCodeFromPreset(colorMixPreset);
     if (colorMixCode) {
       FSSource = vtkShaderProgram.substitute(
@@ -310,7 +317,7 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
       }
       if (
         model.renderable.getLocalAmbientOcclusion() &&
-        actor.getProperty().getAmbient() > 0.0
+        actorProps.getAmbient() > 0.0
       ) {
         FSSource = vtkShaderProgram.substitute(
           FSSource,
@@ -324,7 +331,7 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
     const numIComps = useIndependentComps ? numComp : 1;
     model.gopacity = false;
     for (let nc = 0; !model.gopacity && nc < numIComps; ++nc) {
-      model.gopacity ||= actor.getProperty().getUseGradientOpacity(nc);
+      model.gopacity ||= actorProps.getUseGradientOpacity(nc);
     }
     if (model.gopacity) {
       FSSource = vtkShaderProgram.substitute(
@@ -544,10 +551,11 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
     recomputeLightComplexity(actor, ren.getLights());
 
     const numComp = model.scalarTexture.getComponents();
-    const iComps = actorProps.getIndependentComponents();
     const opacityModes = [];
+    const forceNearestInterps = [];
     for (let nc = 0; nc < numComp; nc++) {
       opacityModes.push(actorProps.getOpacityMode(nc));
+      forceNearestInterps.push(actorProps.getForceNearestInterpolation(nc));
     }
 
     const ext = model.currentInput.getSpatialExtent();
@@ -566,16 +574,17 @@ function vtkOpenGLVolumeMapper(publicAPI, model) {
     const hasZBufferTexture = !!model.zBufferTexture;
 
     const state = {
+      iComps: actorProps.getIndependentComponents(),
       colorMixPreset: actorProps.getColorMixPreset(),
       interpolationType: actorProps.getInterpolationType(),
       useLabelOutline: actorProps.getUseLabelOutline(),
       numComp,
-      iComps,
       maxSamples,
       useGradientOpacity: actorProps.getUseGradientOpacity(0),
       blendMode: model.renderable.getBlendMode(),
       hasZBufferTexture,
       opacityModes,
+      forceNearestInterps,
     };
 
     // We need to rebuild the shader if one of these variables has changed,

diff --git a/Sources/Rendering/OpenGL/glsl/vtkVolumeFS.glsl b/Sources/Rendering/OpenGL/glsl/vtkVolumeFS.glsl
@@ -39,6 +39,9 @@ varying vec3 vertexVCVSOutput;
 // possibly define any "proportional" components
 //VTK::vtkProportionalComponents
 
+// possibly define any components that are forced to nearest interpolation
+//VTK::vtkForceNearestComponents
+
 // Define the blend mode to use
 #define vtkBlendMode //VTK::BlendMode
 
@@ -232,17 +235,39 @@ uniform highp sampler3D texture1;
 vec4 getTextureValue(vec3 pos)
 {
   vec4 tmp = texture(texture1, pos);
-#ifndef UseIndependentComponents
-  #if vtkNumComponents == 1
-    tmp.a = tmp.r;
-  #endif
-  #if vtkNumComponents == 2
-    tmp.a = tmp.g;
+
+  #if defined(vtkComponent0ForceNearest) || \
+      defined(vtkComponent1ForceNearest) || \
+      defined(vtkComponent2ForceNearest) || \
+      defined(vtkComponent3ForceNearest)
+    vec3 nearestPos = (floor(pos * vec3(volumeDimensions)) + 0.5) / vec3(volumeDimensions);
+    vec4 nearestValue = texture(texture1, nearestPos);
+    #ifdef vtkComponent0ForceNearest
+      tmp[0] = nearestValue[0];
+    #endif
+    #ifdef vtkComponent1ForceNearest
+      tmp[1] = nearestValue[1];
+    #endif
+    #ifdef vtkComponent2ForceNearest
+      tmp[2] = nearestValue[2];
+    #endif
+    #ifdef vtkComponent3ForceNearest
+      tmp[3] = nearestValue[3];
+    #endif
   #endif
-  #if vtkNumComponents == 3
-    tmp.a = length(tmp.rgb);
+
+  #ifndef UseIndependentComponents
+    #if vtkNumComponents == 1
+      tmp.a = tmp.r;
+    #endif
+    #if vtkNumComponents == 2
+      tmp.a = tmp.g;
+    #endif
+    #if vtkNumComponents == 3
+      tmp.a = length(tmp.rgb);
+    #endif
   #endif
-#endif
+
   return tmp;
 }