[usdImaging] Implement SamplePrimvar for the native instancer adapter.

Fixes PixarAnimationStudios#996 (Internal change: 2030572)
km4391 · Dec 19, 2019 · 7aa0f5b · 7aa0f5b
1 parent 8e70a72
commit 7aa0f5b
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Showing 2 changed files with 125 additions and 22 deletions.
diff --git a/pxr/usdImaging/usdImaging/instanceAdapter.cpp b/pxr/usdImaging/usdImaging/instanceAdapter.cpp
@@ -764,7 +764,6 @@ struct UsdImagingInstanceAdapter::_GatherInstanceTransformTimeSamplesFn
                     localTimeSamples.begin(), 
                     localTimeSamples.end());
             }
-
         }
         return true;
     }
@@ -788,6 +787,73 @@ UsdImagingInstanceAdapter::_GatherInstanceTransformsTimeSamples(
     return true;
 }
 
+struct UsdImagingInstanceAdapter::_GatherInstancePrimvarTimeSamplesFn
+{
+    _GatherInstancePrimvarTimeSamplesFn(
+        const UsdImagingInstanceAdapter* adapter_,
+        const GfInterval& interval_,
+        TfToken const& key_)
+        : adapter(adapter_), interval(interval_), key(key_)
+    { }
+
+    void Initialize(size_t numInstances)
+    { }
+
+    bool operator()(
+        const std::vector<UsdPrim>& instanceContext, size_t instanceIdx)
+    {
+        SdfPathVector instanceChain;
+        for (UsdPrim const& prim : instanceContext) {
+            instanceChain.push_back(prim.GetPath());
+        }
+        SdfPath instanceChainPath =
+            adapter->_GetPrimPathFromInstancerChain(instanceChain);
+        if (UsdPrim instanceProxyPrim =
+                adapter->_GetPrim(instanceChainPath)) {
+            UsdImaging_InheritedPrimvarStrategy::value_type
+                inheritedPrimvarRecord =
+                    adapter->_GetInheritedPrimvars(instanceProxyPrim);
+            if (inheritedPrimvarRecord) {
+                for (auto const& pv : inheritedPrimvarRecord->primvars) {
+                    if (pv.GetPrimvarName() == key) {
+                        // At this point, pv is the actual primvar attribute
+                        // for this instantiation of instanceContext.
+                        std::vector<double> localTimeSamples;
+                        pv.GetTimeSamplesInInterval(interval, &localTimeSamples);
+
+                        // Join timesamples
+                        result.insert(
+                            result.end(), 
+                            localTimeSamples.begin(), 
+                            localTimeSamples.end());
+                    }
+                }
+            }
+        }
+        return true;
+    }
+
+    const UsdImagingInstanceAdapter* adapter;
+    GfInterval interval;
+    TfToken key;
+    std::vector<double> result;
+};
+
+bool
+UsdImagingInstanceAdapter::_GatherInstancePrimvarTimeSamples(
+    UsdPrim const& instancer,
+    TfToken const& key,
+    GfInterval interval,
+    std::vector<double>* outTimes) const
+{
+    HD_TRACE_FUNCTION();
+
+    _GatherInstancePrimvarTimeSamplesFn gatherSamples(this, interval, key);
+    _RunForAllInstancesToDraw(instancer, &gatherSamples);
+    outTimes->swap(gatherSamples.result);
+    return true;
+}
+
 struct UsdImagingInstanceAdapter::_IsInstanceTransformVaryingFn
 {
     _IsInstanceTransformVaryingFn(const UsdImagingInstanceAdapter* adapter_)
@@ -1540,34 +1606,63 @@ UsdImagingInstanceAdapter::SamplePrimvar(
             maxNumSamples, sampleTimes, sampleValues);
     }
 
+    GfInterval interval = _GetCurrentTimeSamplingInterval();
+    std::vector<double> timeSamples;
+    SdfValueTypeName type;
+
+    if (key != HdInstancerTokens->instanceTransform) {
+        // "instanceTransform" is built-in and synthesized, but other primvars
+        // need to be in the inherited primvar list. Loop through to check
+        // existence and find the correct type.
+        _InstancerData const* instrData =
+            TfMapLookupPtr(_instancerData, usdPrim.GetPath());
+        if (!instrData) {
+            return 0;
+        }
+        bool found = false;
+        for (auto const& ipv : instrData->inheritedPrimvars) {
+            if (ipv.name == key) {
+                type = ipv.type;
+                found = true;
+                break;
+            }
+        }
+        if (!found) {
+            return 0;
+        }
+    }
+
     if (key == HdInstancerTokens->instanceTransform) {
-        GfInterval interval = _GetCurrentTimeSamplingInterval();
-        std::vector<double> timeSamples;
         _GatherInstanceTransformsTimeSamples(usdPrim, interval, &timeSamples);
-        timeSamples.push_back(interval.GetMin());
-        timeSamples.push_back(interval.GetMax());
-
-        // Sort here
-        std::sort(timeSamples.begin(), timeSamples.end());
-        timeSamples.erase(
-            std::unique(timeSamples.begin(), 
-                timeSamples.end()), 
-                timeSamples.end());
-        size_t numSamples = timeSamples.size();
-
-        size_t numSamplesToEvaluate = std::min(maxNumSamples, numSamples);
-        for (size_t i=0; i < numSamplesToEvaluate; ++i) {
-            sampleTimes[i] = timeSamples[i] - time.GetValue();
+    } else {
+        _GatherInstancePrimvarTimeSamples(usdPrim, key, interval, &timeSamples);
+    }
+
+    timeSamples.push_back(interval.GetMin());
+    timeSamples.push_back(interval.GetMax());
+
+    // Sort here
+    std::sort(timeSamples.begin(), timeSamples.end());
+    timeSamples.erase(
+        std::unique(timeSamples.begin(), 
+            timeSamples.end()), 
+            timeSamples.end());
+    size_t numSamples = timeSamples.size();
+    size_t numSamplesToEvaluate = std::min(maxNumSamples, numSamples);
+
+    for (size_t i=0; i < numSamplesToEvaluate; ++i) {
+        sampleTimes[i] = timeSamples[i] - time.GetValue();
+        if (key == HdInstancerTokens->instanceTransform) {
             VtMatrix4dArray xf;
             _ComputeInstanceTransforms(usdPrim, &xf, timeSamples[i]);
             sampleValues[i] = xf;
+        } else {
+            VtValue val;
+            _ComputeInheritedPrimvar(usdPrim, key, type, &val, timeSamples[i]);
+            sampleValues[i] = val;
         }
-        return numSamples;
-    } else {
-        return UsdImagingPrimAdapter::SamplePrimvar(
-            usdPrim, cachePath, key, time,
-            maxNumSamples, sampleTimes, sampleValues);
     }
+    return numSamples;
 }
 
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diff --git a/pxr/usdImaging/usdImaging/instanceAdapter.h b/pxr/usdImaging/usdImaging/instanceAdapter.h
@@ -271,6 +271,14 @@ class UsdImagingInstanceAdapter : public UsdImagingPrimAdapter
                                               std::vector<double>* outTimes) 
                                                   const;
 
+    // Gathers the specified primvar time samples given an instancer.
+    struct _GatherInstancePrimvarTimeSamplesFn;
+    bool _GatherInstancePrimvarTimeSamples(UsdPrim const& instancer,
+                                           TfToken const& key,
+                                           GfInterval interval,
+                                           std::vector<double>* outTimes) 
+                                               const;
+
     // Returns true if any of the instances corresponding to the given
     // instancer has a varying transform.
     struct _IsInstanceTransformVaryingFn;