interpolate ModelFromTrajectory transform

src/mol-plugin-state/animation/built-in/state-interpolation.ts

@@ -6,12 +6,13 @@
 
 import { PluginCommands } from '../../../mol-plugin/commands';
 import { StateTransform } from '../../../mol-state';
+import { shallowEqual } from '../../../mol-util';
 import { ParamDefinition as PD } from '../../../mol-util/param-definition';
 import { PluginStateAnimation } from '../model';
 
 export const AnimateStateInterpolation = PluginStateAnimation.create({
     name: 'built-in.animate-state-interpolation',
-    display: { name: 'Animate State Interpolation' },
+    display: { name: 'Animate State (experimental)' },
     params: () => ({
         transtionDurationInMs: PD.Numeric(2000, { min: 100, max: 30000, step: 10 })
     }),
@@ -42,15 +43,25 @@ export const AnimateStateInterpolation = PluginStateAnimation.create({
 
         for (const s of src) {
             for (const t of tar) {
+                // TODO: better than quadratic alg.
+                // TODO: support for adding/removing nodes
                 if (t.ref !== s.ref) continue;
                 if (t.version === s.version) continue;
 
                 const e = StateTransform.fromJSON(s), f = StateTransform.fromJSON(t);
 
+                const oldState = state.cells.get(s.ref);
+                if (!oldState) continue;
+
+                let newState;
                 if (!e.transformer.definition.interpolate) {
-                    update.to(s.ref).update(currentT <= 0.5 ? e.params : f.params);
+                    newState = currentT <= 0.5 ? e.params : f.params;
                 } else {
-                    update.to(s.ref).update(e.transformer.definition.interpolate(e.params, f.params, currentT, ctx.plugin));
+                    newState = e.transformer.definition.interpolate(e.params, f.params, currentT, ctx.plugin);
+                }
+
+                if (!shallowEqual(oldState, newState)) {
+                    update.to(s.ref).update(newState);
                 }
             }
         }

src/mol-plugin-state/transforms/model.ts

@@ -414,6 +414,10 @@ const ModelFromTrajectory = PluginStateTransform.BuiltIn({
             return new SO.Molecule.Model(model, { label, description });
         });
     },
+    interpolate(a, b, t) {
+        const modelIndex = t >= 1 ? b.modelIndex : a.modelIndex + Math.floor((b.modelIndex - a.modelIndex + 1) * t);
+        return { modelIndex };
+    },
     dispose({ b }) {
         b?.data.customProperties.dispose();
     }

src/mol-plugin/spec.ts

@@ -21,6 +21,7 @@ import { StateActions } from '../mol-plugin-state/actions';
 import { AssignColorVolume } from '../mol-plugin-state/actions/volume';
 import { StateTransforms } from '../mol-plugin-state/transforms';
 import { BoxifyVolumeStreaming, CreateVolumeStreamingBehavior, InitVolumeStreaming } from '../mol-plugin/behavior/dynamic/volume-streaming/transformers';
+import { AnimateStateInterpolation } from '../mol-plugin-state/animation/built-in/state-interpolation';
 
 export { PluginSpec };
 
@@ -126,6 +127,7 @@ export const DefaultPluginSpec = (): PluginSpec => ({
         AnimateModelIndex,
         AnimateCameraSpin,
         AnimateStateSnapshots,
-        AnimateAssemblyUnwind
+        AnimateAssemblyUnwind,
+        AnimateStateInterpolation
     ]
 });