Cool VL Viewer forum

View unanswered posts | View active topics It is currently 2021-10-27 18:47:51



Reply to topic  [ 4 posts ] 
CV 1.25.0.3 Incomplete or Corrupt Textures with HTTP GET 
Author Message

Joined: 2009-03-23 19:07:48
Posts: 30
Reply with quote
Symptom:
Textures (with or without alpha) never completely load or only show corrupted artifacts when using HTTP GET
The corrupted artifacts usually appear as rainbow colored splotches or blobs.
Incomplete textures appeared as blurry low LoD versions of themselves.

Expected Behavor:
Textures appear the same as when loaded via LLUDP.

Steps To Reproduce:
Unable to reproduce on command.

Additional Notes:
However, it seems that these textures only happen when there are more than zero percent dropped packets occurring.
I suspect that the HTTP GET textures are simply incomplete, but being displayed and cached "as-is" in an incomplete state, rather than discarded and re-requested.

I do not have LL viewers installed to compare against.
Does *not* sound the same as SNOW-780 or SNOW-784 based on their descriptions.

Environment
Cool VL Viewer 1.25.0.3

Built with GCC version 40102

You are at 2551936.8, 2569088.3, 23.1 in Ice Moon Exillion located at OSgrid
OpenSim 0.6.9 (Post_Fixes) 0.6.9-post-fixes 116bcb2: 2010-08-21 (Unix/Mono)
Release Notes

CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4000+
Memory: 3964 MB
OS Version: Linux 2.6.34.6-47.fc13.x86_64 #1 SMP Fri Aug 27 08:56:01 UTC 2010 x86_64
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce 8800 GT/PCI/SSE2
OpenGL Version: 3.3.0 NVIDIA 256.35

libcurl Version: libcurl/7.16.4 OpenSSL/0.9.7c zlib/1.2.3 c-ares/1.4.0
J2C Decoder Version: KDU
Audio Driver Version: OpenAL, version 1.1 / OpenAL Community / OpenAL Soft: ALSA Software on default
LLMozLib Version: [LLMediaImplLLMozLib] - 2.01.35371 (Mozilla GRE version 1.8.1.18_0000000000)
Packets Lost: 0/9431 (0.0%)


2010-09-04 17:39:35
Profile

Joined: 2009-03-17 18:42:51
Posts: 4754
Reply with quote
This is not a Cool VL Viewer specific bug, but a bug dealing with the Snowglobe code base (including Snowglobe 2). Please, try with a Snowglobe release and report any bug not already filed in on SL's JIRA (do make a search first, since there are a lot of such bugs reported on the JIRA for Snowglobe already).

Also, if the Cool VL Viewer got the HTTP textures turned off by default, it's for a good reasons: they are unreliable. Turning this setting off (or letting it turned off), will still make the viewer use TCP requests (not UDP like in viewer v1.23), but to the asset server instead of to a HTTP server (SL's Amazon S3 server). The TCP requests are still faster than UDP ones, and in fact, as long as the asset server is responsive enough (not too many Residents connected at once on the grid), they are just as fast as the HTTP texture requests.

EDIT: another issue that could affect textures loading is the MTU of your OS. If your MTU (Maximum Transfer Unit) is too large for your Internet connection (typical problem: MTU set to 1500 for a PPPoA ADSL link that can't take more than 1492 bytes), then you will experience stalling HTTP transfers (this will also show in your web browser for some sites running on servers that can't detect the MTU problem, such as blogspot.com).


2010-09-04 17:53:54
Profile WWW

Joined: 2009-03-23 19:07:48
Posts: 30
Reply with quote
Henri Beauchamp wrote:
This is not a Cool VL Viewer specific bug, but a bug dealing with the Snowglobe code base (including Snowglobe 2). Please, try with a Snowglobe release and report any bug not already filed in on SL's JIRA (do make a search first, since there are a lot of such bugs reported on the JIRA for Snowglobe already).


Yes, I had already done a search on JIRA, which is why I included the comment about the rainbow textures I was seeing not sounding like SNOW-780 or SNOW-784.

Henri Beauchamp wrote:
Also, if the Cool VL Viewer got the HTTP textures turned off by default, it's for a good reasons: they are unreliable. Turning this setting off (or letting it turned off), will still make the viewer use TCP requests (not UDP like in viewer v1.23), but to the asset server instead of to a HTTP server (SL's Amazon S3 server). The TCP requests are still faster than UDP ones, and in fact, as long as the asset server is responsive enough (not too many Residents connected at once on the grid), they are just as fast as the HTTP texture requests.


Well, you may have hit on it - HTTP is unreliable. TCP is more reliable as long as load is low.
What puzzles me is why it looks like the textures get chopped off before being completely downloaded, cached that way, and used.
That's what I was trying to point out.
Maybe the S3 based textures only add to the problem.
Will let the Snowstorm and Snowglobe folks sort it out I guess.

Henri Beauchamp wrote:
EDIT: another issue that could affect textures loading is the MTU of your OS. If your MTU (Maximum Transfer Unit) is too large for your Internet connection (typical problem: MTU set to 1500 for a PPPoA ADSL link that can't take more than 1492 bytes), then you will experience stalling HTTP transfers (this will also show in your web browser for some sites running on servers that can't detect the MTU problem, such as blogspot.com).


Not a worry here, but an interesting debug note for people to have in general.
If there's a mismatch here, it's somewhere on the red side of my router where I can't make any changes anyway.

Thanks for taking a look!


2010-09-04 21:06:23
Profile

Joined: 2009-03-17 18:42:51
Posts: 4754
Reply with quote
Allen Kerensky wrote:
What puzzles me is why it looks like the textures get chopped off before being completely downloaded, cached that way, and used.
There are bugs in the texture pipeline, such as dead locks that prevent the textures to get fully downloaded (some parts of the code are not thread-safe and this seems to be worked upon by Aleric Inglewood for Snowglobe). You may also try and experiment with the "Run Multiple Threads" Advanced->Rendering setting (disabling it or enabling it) and see if it works any better...

Henri Beauchamp wrote:
EDIT: another issue that could affect textures loading is the MTU of your OS. If your MTU (Maximum Transfer Unit) is too large for your Internet connection (typical problem: MTU set to 1500 for a PPPoA ADSL link that can't take more than 1492 bytes), then you will experience stalling HTTP transfers (this will also show in your web browser for some sites running on servers that can't detect the MTU problem, such as blogspot.com).
Allen Kerensky wrote:
Not a worry here, but an interesting debug note for people to have in general.
If there's a mismatch here, it's somewhere on the red side of my router where I can't make any changes anyway.
Yes you can... Just adjust your MTU to the right size (the one the router lets go through). Also, with an ADSL link over ATM, lowering the MTU to a multiple of the ATM cell size (+overhead), increases the throughput: 1478 is the right MTU for this kind of link (even though anything up to 1492 will do, but at a lesser throughput).


2010-09-04 21:18:52
Profile WWW
Display posts from previous:  Sort by  
Reply to topic   [ 4 posts ] 

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software.