Difference between revisions of "Streaming Cost test"

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== Tests ==
== Tests ==


Target viewport streaming cost at 128m, medium detail (currently 2MB)
Target visible triangles from center of region at medium mesh detail (in preferences) is 250 thousand triangles.
 
<br>
* "I got this number by flying around some prim heavy builds (the city north of Ahern) with all rendering disabled but prims, view distance set to 128m, and prim detail set to mid, and watching the peak triangle count per frame in the statistic floater. The average was around 75k/triangles per frame with a peak of 150k, so for meshes a good target would be 125k. On MeshHQ 3, after disabling all rendering but prims (meshes fall under the same category as prims in the render pipeline), the peak triangle count per frame was close to 300k/triangles. On that build, there was no LoD enforcement and a ratio of 8KB/prim for mesh costs, so I'm hoping with a ratio of 4KB/prim and strict LoD enforcement, recreating that build within the new criteria will result in under 125k/triangles per frame."
To verify a mesh object's streaming cost is being calculated correctly:
 
* Open preferences->graphics and click "Reset"
* Ensure that Mesh detail: Objects is set to "Mid"
* Set draw distance to 256m or greater
* Go to a flat, empty region
* Place a copy of the mesh object in a corner of the sim
* Set the mesh physics shape type to "convex hull" and ensure that the prim equivalence cost matches the object's streaming cost (bound by streaming cost, not physics cost)
* Move your avatar to the center of the sim
* If necessary, scale the mesh object up so that it remains visible from the center of the region when placed at a region corner (prevent object from disappearing due to interest list)
* Place copies of the mesh around the region, distributing evenly at ground level, until the simulator reports the parcel is full
* Stand at the center of the sim, and do a complete 360 degree turn, ensuring every copy of the mesh object is loaded at appropriate LoD.
* Open develop->consoles->scene statistics
* Ensure "Region Object Streaming Cost" is approximately 15000
* Ensure "Visible" entry for "Region Object Triangle Counts" indicates approximately 250 thousand triangles are visible.
<br>
If visible triangles is too high, the streaming cost is being too forgiving for the mesh object in question.  If it's too low, streaming cost is being too strict.


== Verify duck.dae cost ==
== Verify duck.dae cost ==

Revision as of 12:54, 28 June 2011

Test Plan Name:

Streaming Cost test

Sources

https://wiki.secondlife.com/wiki/Mesh/Mesh_Streaming_Cost
https://wiki.secondlife.com/wiki/Mesh_Accounting_Test

Purpose

Verify the amount of data streamed to the viewer is within the expected range.

Tests

Target visible triangles from center of region at medium mesh detail (in preferences) is 250 thousand triangles.
To verify a mesh object's streaming cost is being calculated correctly:

  • Open preferences->graphics and click "Reset"
  • Ensure that Mesh detail: Objects is set to "Mid"
  • Set draw distance to 256m or greater
  • Go to a flat, empty region
  • Place a copy of the mesh object in a corner of the sim
  • Set the mesh physics shape type to "convex hull" and ensure that the prim equivalence cost matches the object's streaming cost (bound by streaming cost, not physics cost)
  • Move your avatar to the center of the sim
  • If necessary, scale the mesh object up so that it remains visible from the center of the region when placed at a region corner (prevent object from disappearing due to interest list)
  • Place copies of the mesh around the region, distributing evenly at ground level, until the simulator reports the parcel is full
  • Stand at the center of the sim, and do a complete 360 degree turn, ensuring every copy of the mesh object is loaded at appropriate LoD.
  • Open develop->consoles->scene statistics
  • Ensure "Region Object Streaming Cost" is approximately 15000
  • Ensure "Visible" entry for "Region Object Triangle Counts" indicates approximately 250 thousand triangles are visible.


If visible triangles is too high, the streaming cost is being too forgiving for the mesh object in question. If it's too low, streaming cost is being too strict.

Verify duck.dae cost

  • Upload model, choose duck.dae
  • In the Physics tab of the upload window, choose "Use Level of Detail: Lowest" LOD
  • Click Analyze. Click Simplify. Click Upload.
  • Rez the duck.
  • Resize the duck to 1x1x1m
  • Edit the duck and Verify the resource cost is 3.
  • Resize the duck to 10x10x10m
  • Edit the duck and Verify the resource cost is 7.
  • Resize the duck to 20x20x20m
  • Edit the duck and Verify the resource cost is 11.
  • Resize the duck to 64x64x64m
  • Edit the duck and Verify the resource cost is 24.


Streaming Cost = (MAX(256-Dlowest, 1.0)/32 * KBYTES_IN_LOWEST + MAX(Dlowest-Dlow, 1.0)/32 * KBYTES_IN_LOW + MAX(Dlow - Dmid, 1.0)/32 * KBYTES_IN_MID + MAX(Dmid, 1.0)/32 * KBYTES_IN_HIGH) * COST_SCALER

How can I see KBYTES_IN_LOWEST, KBYTES_IN_LOW, KBYTES_IN_MID and KBYTES_IN_HIGH

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