Exemplo n.º 1
0
void
PxrUsdKatanaReadPointInstancer(
        const UsdGeomPointInstancer& instancer,
        const PxrUsdKatanaUsdInPrivateData& data,
        PxrUsdKatanaAttrMap& instancerAttrMap,
        PxrUsdKatanaAttrMap& sourcesAttrMap,
        PxrUsdKatanaAttrMap& instancesAttrMap,
        PxrUsdKatanaAttrMap& inputAttrMap)
{
    const double currentTime = data.GetCurrentTime();

    PxrUsdKatanaReadXformable(instancer, data, instancerAttrMap);

    // Get primvars for setting later. Unfortunatley, the only way to get them
    // out of the attr map is to build it, which will cause its contents to be
    // cleared. We'll need to restore its contents before continuing.
    //
    FnKat::GroupAttribute instancerAttrs = instancerAttrMap.build();
    FnKat::GroupAttribute primvarAttrs =
            instancerAttrs.getChildByName("geometry.arbitrary");
    for (int64_t i = 0; i < instancerAttrs.getNumberOfChildren(); ++i)
    {
        instancerAttrMap.set(instancerAttrs.getChildName(i),
                instancerAttrs.getChildByIndex(i));
    }

    instancerAttrMap.set("type", FnKat::StringAttribute("usd point instancer"));

    const std::string fileName = data.GetUsdInArgs()->GetFileName();
    instancerAttrMap.set("info.usd.fileName", FnKat::StringAttribute(fileName));

    FnKat::GroupAttribute inputAttrs = inputAttrMap.build();

    const std::string katOutputPath = FnKat::StringAttribute(
            inputAttrs.getChildByName("outputLocationPath")).getValue("", false);
    if (katOutputPath.empty())
    {
        _LogAndSetError(instancerAttrMap, "No output location path specified");
        return;
    }

    //
    // Validate instancer data.
    //

    const std::string instancerPath = instancer.GetPath().GetString();

    UsdStageWeakPtr stage = instancer.GetPrim().GetStage();

    // Prototypes (required)
    //
    SdfPathVector protoPaths;
    instancer.GetPrototypesRel().GetTargets(&protoPaths);
    if (protoPaths.empty())
    {
        _LogAndSetError(instancerAttrMap, "Instancer has no prototypes");
        return;
    }

    _PathToPrimMap primCache;
    for (auto protoPath : protoPaths) {
        const UsdPrim &protoPrim = stage->GetPrimAtPath(protoPath);
        primCache[protoPath] = protoPrim;
    }

    // Indices (required)
    //
    VtIntArray protoIndices;
    if (!instancer.GetProtoIndicesAttr().Get(&protoIndices, currentTime))
    {
        _LogAndSetError(instancerAttrMap, "Instancer has no prototype indices");
        return;
    }
    const size_t numInstances = protoIndices.size();
    if (numInstances == 0)
    {
        _LogAndSetError(instancerAttrMap, "Instancer has no prototype indices");
        return;
    }
    for (auto protoIndex : protoIndices)
    {
        if (protoIndex < 0 || static_cast<size_t>(protoIndex) >= protoPaths.size())
        {
            _LogAndSetError(instancerAttrMap, TfStringPrintf(
                    "Out of range prototype index %d", protoIndex));
            return;
        }
    }

    // Mask (optional)
    //
    std::vector<bool> pruneMaskValues =
            instancer.ComputeMaskAtTime(currentTime);
    if (!pruneMaskValues.empty() and pruneMaskValues.size() != numInstances)
    {
        _LogAndSetError(instancerAttrMap,
                "Mismatch in length of indices and mask");
        return;
    }

    // Positions (required)
    //
    UsdAttribute positionsAttr = instancer.GetPositionsAttr();
    if (!positionsAttr.HasValue())
    {
        _LogAndSetError(instancerAttrMap, "Instancer has no positions");
        return;
    }

    //
    // Compute instance transform matrices.
    //

    const double timeCodesPerSecond = stage->GetTimeCodesPerSecond();

    // Gather frame-relative sample times and add them to the current time to
    // generate absolute sample times.
    //
    const std::vector<double> &motionSampleTimes =
        data.GetMotionSampleTimes(positionsAttr);
    const size_t sampleCount = motionSampleTimes.size();
    std::vector<UsdTimeCode> sampleTimes(sampleCount);
    for (size_t a = 0; a < sampleCount; ++a)
    {
        sampleTimes[a] = UsdTimeCode(currentTime + motionSampleTimes[a]);
    }

    // Get velocityScale from the opArgs.
    //
    float velocityScale = FnKat::FloatAttribute(
        inputAttrs.getChildByName("opArgs.velocityScale")).getValue(1.0f, false);

    // XXX Replace with UsdGeomPointInstancer::ComputeInstanceTransformsAtTime.
    //
    std::vector<std::vector<GfMatrix4d>> xformSamples(sampleCount);
    const size_t numXformSamples =
        _ComputeInstanceTransformsAtTime(xformSamples, instancer, sampleTimes,
            UsdTimeCode(currentTime), timeCodesPerSecond, numInstances,
            positionsAttr, velocityScale);
    if (numXformSamples == 0) {
        _LogAndSetError(instancerAttrMap, "Could not compute "
                                          "sample/topology-invarying instance "
                                          "transform matrix");
        return;
    }

    //
    // Compute prototype bounds.
    //

    bool aggregateBoundsValid = false;
    std::vector<double> aggregateBounds;

    // XXX Replace with UsdGeomPointInstancer::ComputeExtentAtTime.
    //
    VtVec3fArray aggregateExtent;
    if (_ComputeExtentAtTime(
            aggregateExtent, data.GetUsdInArgs(), xformSamples,
            motionSampleTimes, protoIndices, protoPaths, primCache,
            pruneMaskValues)) {
        aggregateBoundsValid = true;
        aggregateBounds.resize(6);
        aggregateBounds[0] = aggregateExtent[0][0]; // min x
        aggregateBounds[1] = aggregateExtent[1][0]; // max x
        aggregateBounds[2] = aggregateExtent[0][1]; // min y
        aggregateBounds[3] = aggregateExtent[1][1]; // max y
        aggregateBounds[4] = aggregateExtent[0][2]; // min z
        aggregateBounds[5] = aggregateExtent[1][2]; // max z
    }

    //
    // Build sources. Keep track of which instances use them.
    //

    FnGeolibServices::StaticSceneCreateOpArgsBuilder sourcesBldr(false);

    std::vector<int> instanceIndices;
    instanceIndices.reserve(numInstances);

    std::vector<std::string> instanceSources;
    instanceSources.reserve(protoPaths.size());

    std::map<std::string, int> instanceSourceIndexMap;

    std::vector<int> omitList;
    omitList.reserve(numInstances);

    std::map<SdfPath, std::string> protoPathsToKatPaths;

    for (size_t i = 0; i < numInstances; ++i)
    {
        int index = protoIndices[i];

        // Check to see if we are pruned.
        //
        bool isPruned = (!pruneMaskValues.empty() and
                         pruneMaskValues[i] == false);
        if (isPruned)
        {
            omitList.push_back(i);
        }

        const SdfPath &protoPath = protoPaths[index];

        // Compute the full (Katana) path to this prototype.
        //
        std::string fullProtoPath;
        std::map<SdfPath, std::string>::const_iterator pptkpIt =
                protoPathsToKatPaths.find(protoPath);
        if (pptkpIt != protoPathsToKatPaths.end())
        {
            fullProtoPath = pptkpIt->second;
        }
        else
        {
            _PathToPrimMap::const_iterator pcIt = primCache.find(protoPath);
            const UsdPrim &protoPrim = pcIt->second;
            if (!protoPrim) {
                continue;
            }

            // Determine where (what path) to start building the prototype prim
            // such that its material bindings will be preserved. This could be
            // the prototype path itself or an ancestor path.
            //
            SdfPathVector commonPrefixes;

            UsdRelationship materialBindingsRel =
                    UsdShadeMaterial::GetBindingRel(protoPrim);

            auto assetAPI = UsdModelAPI(protoPrim);
            std::string assetName;
            bool isReferencedModelPrim =
                    assetAPI.IsModel() and assetAPI.GetAssetName(&assetName);

            if (!materialBindingsRel or isReferencedModelPrim)
            {
                // The prim has no material bindings or is a referenced model
                // prim (meaning that materials are defined below it); start
                // building at the prototype path.
                //
                commonPrefixes.push_back(protoPath);
            }
            else
            {
                SdfPathVector materialPaths;
                materialBindingsRel.GetForwardedTargets(&materialPaths);
                for (auto materialPath : materialPaths)
                {
                    const SdfPath &commonPrefix =
                            protoPath.GetCommonPrefix(materialPath);
                    if (commonPrefix.GetString() == "/")
                    {
                        // XXX Unhandled case.
                        // The prototype prim and its material are not under the
                        // same parent; start building at the prototype path
                        // (although it is likely that bindings will be broken).
                        //
                        commonPrefixes.push_back(protoPath);
                    }
                    else
                    {
                        // Start building at the common ancestor between the
                        // prototype prim and its material.
                        //
                        commonPrefixes.push_back(commonPrefix);
                    }
                }
            }

            // XXX Unhandled case.
            // We'll use the first common ancestor even if there is more than
            // one (which shouldn't appen if the prototype prim and its bindings
            // are under the same parent).
            //
            SdfPath::RemoveDescendentPaths(&commonPrefixes);
            const std::string buildPath = commonPrefixes[0].GetString();

            // See if the path is a child of the point instancer. If so, we'll
            // match its hierarchy. If not, we'll put it under a 'prototypes'
            // group.
            //
            std::string relBuildPath;
            if (pystring::startswith(buildPath, instancerPath + "/"))
            {
                relBuildPath = pystring::replace(
                        buildPath, instancerPath + "/", "");
            }
            else
            {
                relBuildPath = "prototypes/" +
                        FnGeolibUtil::Path::GetLeafName(buildPath);
            }

            // Start generating the full path to the prototype.
            //
            fullProtoPath = katOutputPath + "/" + relBuildPath;

            // Make the common ancestor our instance source.
            //
            sourcesBldr.setAttrAtLocation(relBuildPath,
                    "type", FnKat::StringAttribute("instance source"));

            // Author a tracking attr.
            //
            sourcesBldr.setAttrAtLocation(relBuildPath,
                    "info.usd.sourceUsdPath",
                    FnKat::StringAttribute(buildPath));

            // Tell the BuildIntermediate op to start building at the common
            // ancestor.
            //
            sourcesBldr.setAttrAtLocation(relBuildPath,
                    "usdPrimPath", FnKat::StringAttribute(buildPath));
            sourcesBldr.setAttrAtLocation(relBuildPath,
                    "usdPrimName", FnKat::StringAttribute("geo"));

            if (protoPath.GetString() != buildPath)
            {
                // Finish generating the full path to the prototype.
                //
                fullProtoPath = fullProtoPath + "/geo" + pystring::replace(
                        protoPath.GetString(), buildPath, "");
            }

            // Create a mapping that will link the instance's index to its
            // prototype's full path.
            //
            instanceSourceIndexMap[fullProtoPath] = instanceSources.size();
            instanceSources.push_back(fullProtoPath);

            // Finally, store the full path in the map so we won't have to do
            // this work again.
            //
            protoPathsToKatPaths[protoPath] = fullProtoPath;
        }

        instanceIndices.push_back(instanceSourceIndexMap[fullProtoPath]);
    }

    //
    // Build instances.
    //

    FnGeolibServices::StaticSceneCreateOpArgsBuilder instancesBldr(false);

    instancesBldr.createEmptyLocation("instances", "instance array");

    instancesBldr.setAttrAtLocation("instances",
            "geometry.instanceSource",
                    FnKat::StringAttribute(instanceSources, 1));

    instancesBldr.setAttrAtLocation("instances",
            "geometry.instanceIndex",
                    FnKat::IntAttribute(&instanceIndices[0],
                            instanceIndices.size(), 1));

    FnKat::DoubleBuilder instanceMatrixBldr(16);
    for (size_t a = 0; a < numXformSamples; ++a) {

        double relSampleTime = motionSampleTimes[a];

        // Shove samples into the builder at the frame-relative sample time. If
        // motion is backwards, make sure to reverse time samples.
        std::vector<double> &matVec = instanceMatrixBldr.get(
            data.IsMotionBackward()
                ? PxrUsdKatanaUtils::ReverseTimeSample(relSampleTime)
                : relSampleTime);

        matVec.reserve(16 * numInstances);
        for (size_t i = 0; i < numInstances; ++i) {

            GfMatrix4d instanceXform = xformSamples[a][i];
            const double *matArray = instanceXform.GetArray();

            for (int j = 0; j < 16; ++j) {
                matVec.push_back(matArray[j]);
            }
        }
    }
    instancesBldr.setAttrAtLocation("instances",
            "geometry.instanceMatrix", instanceMatrixBldr.build());

    if (!omitList.empty())
    {
        instancesBldr.setAttrAtLocation("instances",
                "geometry.omitList",
                        FnKat::IntAttribute(&omitList[0], omitList.size(), 1));
    }

    instancesBldr.setAttrAtLocation("instances",
            "geometry.pointInstancerId",
                    FnKat::StringAttribute(katOutputPath));

    //
    // Transfer primvars.
    //

    FnKat::GroupBuilder instancerPrimvarsBldr;
    FnKat::GroupBuilder instancesPrimvarsBldr;
    for (int64_t i = 0; i < primvarAttrs.getNumberOfChildren(); ++i)
    {
        const std::string primvarName = primvarAttrs.getChildName(i);

        // Use "point" scope for the instancer.
        instancerPrimvarsBldr.set(primvarName, primvarAttrs.getChildByIndex(i));
        instancerPrimvarsBldr.set(primvarName + ".scope",
                FnKat::StringAttribute("point"));

        // User "primitive" scope for the instances.
        instancesPrimvarsBldr.set(primvarName, primvarAttrs.getChildByIndex(i));
        instancesPrimvarsBldr.set(primvarName + ".scope",
                FnKat::StringAttribute("primitive"));
    }
    instancerAttrMap.set("geometry.arbitrary", instancerPrimvarsBldr.build());
    instancesBldr.setAttrAtLocation("instances",
            "geometry.arbitrary", instancesPrimvarsBldr.build());

    //
    // Set the final aggregate bounds.
    //

    if (aggregateBoundsValid)
    {
        instancerAttrMap.set("bound", FnKat::DoubleAttribute(&aggregateBounds[0], 6, 2));
    }

    //
    // Set proxy attrs.
    //

    instancerAttrMap.set("proxies", PxrUsdKatanaUtils::GetViewerProxyAttr(data));

    //
    // Transfer builder results to our attr maps.
    //

    FnKat::GroupAttribute sourcesAttrs = sourcesBldr.build();
    for (int64_t i = 0; i < sourcesAttrs.getNumberOfChildren(); ++i)
    {
        sourcesAttrMap.set(
                sourcesAttrs.getChildName(i),
                sourcesAttrs.getChildByIndex(i));
    }

    FnKat::GroupAttribute instancesAttrs = instancesBldr.build();
    for (int64_t i = 0; i < instancesAttrs.getNumberOfChildren(); ++i)
    {
        instancesAttrMap.set(
                instancesAttrs.getChildName(i),
                instancesAttrs.getChildByIndex(i));
    }
}