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FSXA texture vertices limit?

Horst18519

Horst18519

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I wonder if anybody came across this before:
We seem to have hit some limit in the FSX autogen engine. We created some agn objects and annotated a LC texture with them. The objects have around 500 polys, up to 50 of them are placed on one LC texture.
In FSX, those objects flicker randomly, something I couldn't explain until I found that the denser the autogen setting and the more objects annotated on the LC, the more likely the objects are to start flickering.

I guess this is the 65.000 texture vertices limit? As agn is batched it kinda makes sense that this limit exists for agn as well, but I expected FSX to work around this - if Arno coded it, it sure would. :D

Anybody had that problem before? We seem to have a similar problem with library objects that are placed densely in a small area (all sharing the same texture with drawcall batching active), maybe that's the same issue.
 
Hi Thorsten,

Ian mentioned some limit on the amount of library objects recently.

50 polygons on a tile does not sound much. I have done tests with many vegetation and buildings on a tile and did not see flickering. Be aware, that was not LC, but photo scenery.
 
Hi Thorsten:

It would be interesting indeed to know if there were a separate FS rendering engine limitation based on vertices per cell or draw calls "PER_CELL".

However, I am compelled to first inquire what the effective density of the annotated autogen objects are as a function of the size of your land class area (in terms of a quad matrix / LOD tile size) , so that we might interpret this expressed as ex: objects "PER_CELL" ? :confused:



Does the run time rendering change (more or less 'flickering') with use of the autogen attenuation tweaks "PER_CELL" ?



When I saw this post, I wondered what FS computer hardware you are testing on, and also was reminded of this thread:

http://www.fsdeveloper.com/forum/showthread.php?t=18250&highlight=Holger ?



I was additionally reminded of how Holger once showed us a test example of massive autogen annotation density in a scene, which might once again merit review to illustrate what the FSX rendering engine may actually be able to cope with "PER_CELL", as seen in this 'archived' thread:

http://www.fsdeveloper.com/forum/attachment.php?attachmentid=8147&d=1284049512

< ...After unzipping to a folder, just double-click "FSX - Holger's Autogen Tweak - AVSIM controversy with Nick_N.htm" >


...as cited in this thread on that topic:

http://www.fsdeveloper.com/forum/showpost.php?p=141363&postcount=6


Hope these factors might help one better interpret and possibly shed some more light on the intriguing scenario you have described here. :)

GaryGB
 
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I was also reminded of my problem back then with Cuzco, when I placed tons of autogen in the city, but back then it was more likely some gfx card overflow.
This time, the issue is reproducable on different systems and seems to be an FSX limit we broke.
It's in fact not a high number of objects we're talking about, but an approx number of 40.000 or so polys per LC cell. Maybe I should do a test here to find the exact limit.
 
Horst18519 said:
It's in fact not a high number of objects we're talking about, but an approx number of 40.000 or so polys per LC cell. Maybe I should do a test here to find the exact limit.
Click to expand...

So, then the "polygons" in your test scenario are not Trees, Buildings, or other objects vertically positioned perpendicular to the terrain mesh surface with multiple texture vertices per polygon object such as seen with "3D" scenery objects (ex: having Length, Width, and Height) ? :confused:

Assuming these are "flat" and/or mesh-clinging land class texture "vector" polygons, it would be interesting to know if FSX still imposes a limit as to 'texture' vertex count per object (which IIRC, for "3D" objects was considered more of a concern for both geometry and texture mapping ...than total 'polygon' or 'triangle' count).


One might wonder if, when texture draw call batching is used for a scene full of objects, that scenario is vulnerable to a FSX texture vertex limit "PER_CELL" ...as a cumulative total of the texture vertex load which incrementally accumulates per individual object. :scratchch

GaryGB
 
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No, they are 3D buildings, just a bit more complex than usual (up to 500 polys per model).
 
Are we taking about library objects here or about autogen generic buildings?

I am not sure what limits there are for autogen objects and if they are the same as mdl objects placed with bglcomp.

Some time ago I found out that with drawcall batching enabled you still can't have more than around 50000 triangles per material (would have to look up the more accurate number I found that time). If there are more triangles, you would have to break the drawcall batching to see them. Maybe something similar happens here.
 
The exact number I found then was 43690 triangles. Above that amount I needed to add the empty xanim (and thus break drawcall batching) to see the objects. Else nothing would appear.
 
In my case, I can actually see the objects, but they flicker permanently in a random way.
It happens to both, custom library objects and custom autogen objects (annotated on LC textures). Looks like FSX can't batch drawcalls if you exceed those numbers.
 
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