From 7bceea80d4a04649f495f4f4331d7e3bdcdb05ca Mon Sep 17 00:00:00 2001 From: Marijn Tamis Date: Wed, 12 Sep 2018 14:12:47 +0200 Subject: 1.1.5 Release (24934621) --- .../documentation/Cooking/TripletScheduler.html | 278 +++++++++++++++++++++ 1 file changed, 278 insertions(+) create mode 100644 NvCloth/docs/documentation/Cooking/TripletScheduler.html (limited to 'NvCloth/docs/documentation/Cooking/TripletScheduler.html') diff --git a/NvCloth/docs/documentation/Cooking/TripletScheduler.html b/NvCloth/docs/documentation/Cooking/TripletScheduler.html new file mode 100644 index 0000000..7b3dacc --- /dev/null +++ b/NvCloth/docs/documentation/Cooking/TripletScheduler.html @@ -0,0 +1,278 @@ + + + + + + + + + TripletScheduler — NvCloth 1.1.3 documentation + + + + + + + + + + + + + + + + + + + +
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TripletScheduler

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AdjacencyQuerier

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AdjacencyQuerier is a helper class that produces lists of adjacent triplets (triangles) for particles, from the given list of triangles. +The algorithm to generate these lists is described in this section.

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The result will be stored in one continuous array, instead of separate allocations. +For all particles we count how often each particle is referenced by a triangle and store this in adjacencyCount[i] for particle i. +This will determine the size of the individual adjacency lists. +Next, we calculate the inclusive prefix sum of adjacencyCount and store it in mAdjacencyIndecies (which contains one element more than adjacencyCount, for later use). +Now the last element of mAdjacencyIndecies contains the total size of all adjacency lists combined, so mAdjacencies can be allocated.

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To generate the adjacency lists we loop through all triplets and store the triplet index in the adjacency list of each particle. +We use mAdjacencyIndecies[i]-1 to find the beginning of the adjacency list inside mAdjacencies for particle i. +mAdjacencyIndecies[i] is decremented so the next one will be written in a new location. +The values in mAdjacencyIndecies will be decremented to be the exclusive prefix sum after all the lists are filled (still pointing to all the beginnings of the lists). +The extra element can be used so that the list range can be given like Range<uint32_t>(mAdjacencies[mAdjacencyIndecies[i]],mAdjacencies[mAdjacencyIndecies[i+1]]) without going out of bounds for the last list.

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The following tables give example values for the arrays with a square cloth plane of 9 particles (without alternating diagonals):

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TripletScheduler

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The triplet scheduler is used to order triplets so that multiple can be processed in parralell (using simd, or gpu parralelism). +The triplets need to be reordered in a way that only unique particles are processed at the same time to avoid race conditions and/or result stomping.

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TripletScheduler::simd()

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This function is used to sort triplets for simd processing on the cpu. +The input mTriplets will be reordered in place to create batches of simdWidth triplets that don’t share particles. +We keep track of sets of batches, instead of adding padding when a batch cannot be filled. +A set is a range of triplets that is successfully divided in batches. +A new set should only start after a batch could not be filled with unique triplets. +We also track the total amount of padding needed to make the set sizes a multiple of simdWidth, which is used to reserve the size of mPaddedTriplets. +Now each set can be copied into mPaddedTriplets with the correct padding without having to resize the list. (this used to be done in SwCloth::setVirtualParticles).

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TripletScheduler::warp()

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This function is used to sort triplets for cuda/gpu processing. +It will generate sets of triplets that can be processed in parallel in a cuda warp, ensuring that no duplicate particles are processed in parallel. +It also optimizes the sets to have the least amount of bank conflicts possible.

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