Difference between revisions of "PDR.PODM Distributed Memory"

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(Current Issues)
(Current Issues)
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* No reuse of leaves refined by worker nodes. The picture below shows the issue. Two neighbour leaves (0,1) each refined as the main leaf (0 top, 1 bottom) but not refined as a neighor.
 
* No reuse of leaves refined by worker nodes. The picture below shows the issue. Two neighbour leaves (0,1) each refined as the main leaf (0 top, 1 bottom) but not refined as a neighor.
 
[[File:PDR_PODM_Leaves_not_refined.png| 700px]]
 
[[File:PDR_PODM_Leaves_not_refined.png| 700px]]
* Current algorithm uses neighbor tranversal to distribute cells to octree leaving some cells out in some cases. Such a case can happen when a cell is part of an octree leaf based on its circumcenter but  
+
* Current algorithm uses neighbour traversal to distribute cells to octree leaving some cells out in some cases. Such a case can happen when a cell is part of an octree leaf based on its circumcenter but  
it does not have any neighbor in the same leaf.
+
it does not have any neighbour in the same leaf.
  
 
[[File:PDR_PODM_Cells_not_distributed.png| 700px]]
 
[[File:PDR_PODM_Cells_not_distributed.png| 700px]]
 +
 +
* Another issue comes from the fact that incident cells of vertices are not handled correctly when the vertex is packed and migrated. Specifically, when the incident cell of a vertex is not part of the
 +
working unit (leaf + lvl. 1 neighbours) the vertex is given the infinite cell as incident. As a result the PODM code does not work correctly causing it too crash randomly.
 +
 +
* The function that unpacks the required leaves before refinement does discard duplicate vertices. Duplicate vertices will always be present since each leaf is packed and sent individually, and as a result,
 +
neighbouring leaves will include the shared vertices.

Revision as of 17:05, 6 April 2020

Current Issues

  • No reuse of leaves refined by worker nodes. The picture below shows the issue. Two neighbour leaves (0,1) each refined as the main leaf (0 top, 1 bottom) but not refined as a neighor.

PDR PODM Leaves not refined.png

  • Current algorithm uses neighbour traversal to distribute cells to octree leaving some cells out in some cases. Such a case can happen when a cell is part of an octree leaf based on its circumcenter but

it does not have any neighbour in the same leaf.

PDR PODM Cells not distributed.png

  • Another issue comes from the fact that incident cells of vertices are not handled correctly when the vertex is packed and migrated. Specifically, when the incident cell of a vertex is not part of the

working unit (leaf + lvl. 1 neighbours) the vertex is given the infinite cell as incident. As a result the PODM code does not work correctly causing it too crash randomly.

  • The function that unpacks the required leaves before refinement does discard duplicate vertices. Duplicate vertices will always be present since each leaf is packed and sent individually, and as a result,

neighbouring leaves will include the shared vertices.