I am fooling around with my settings in P3D and noticed I have tessellation full right. That might be a bit too much and causing some problems. However, I don't have a clue what the various settings for tessellation do... Anyone has an idea what a difference that slider might make? (I can of course simply test it and I will but it's a bit hard to test if you don't know what to look for in the sim.)

Glad someone asked that question, I would also like to know.

 

Sent from my Mobile thing

 

 

It should be controlling 'hardware tessellation' which is a feature of DX11 and compatible cards, basically, 3d models (usually specifically landscape, but other objects can have it applied too) are sent to the card in a lower resolution (or in this case, in the normal FSX resolution), and the video card can 'fill in' other points and create a higher resolution model. With landscape - which is likely all P3d sends with tessellation turned on - it should mean that you get a more realistic landscape, especially in mountainous areas where the difference between two terrain points can be quite big.

 

Towards the end of this ATI video (not P3D, but some demo ATI made):

 

 

You can see how altering the tesselation level controls how simple<>complex the mountains look. The effect of hardware tessellation really depends on a lot of factors, and it may take a while before we see scenery that truly makes the best use of it (usually you use the 'normal map' of the landscape to provide the hinting to the tessellator, so we may need scenery with normal mapping applied, if it's even possible).

http://forum.avsim.net/topic/427235-two-questions-tesselation-factor-texture-resolution/#entry2861651

Tessalation kills my GTX580 and takes my VRAM usage straight up to 95%, so it's a no go for me until I get a better card. A 3GB card will be needed.

I did some tests, and going full rightt with Tesselation seems to offer only a very minor visual improvement. A notch down doesn't seem to have much impact on my performance (YMMV), and looks nearly identical.

I am 1 notch up from the left on the Tesselation slider - maybe that explains my high frame rates in virtually all scenarios.

http://forum.avsim.net/topic/427235-two-questions-tesselation-factor-texture-resolution/#entry2861651

That...

 

I'm not sure how AMD handles the tessellation, but nVidia cards at highest setting provide a 1,000x increase in virtual polygons...

Just an FYI - tessellation can eat frames even on modern GPU benchmark tests. So I would be careful with this slider.

That...

 

I'm not sure how AMD handles the tessellation, but nVidia cards at highest setting provide a 1,000x increase in virtual polygons...

 

Really depends on which GPU...from Tahiti onwards they are about equal on the high end.

 

Cayman was horrible, with Pitcairn improving on Cayman by a good bit.

Tessalation kills my GTX580 and takes my VRAM usage straight up to 95%, so it's a no go for me until I get a better card. A 3GB card will be needed.

 

I have a 660TI and have tessellation set to the extreme right. I get constant OOM errors. Others have told me this is not VRAM related - is this true? 

Tesselation is like a polygon interpolator/fractal cutter.

 

In Prepar3D it will be used for interpolating the Terrain Mesh by using repetitive shapes, the higher the tesselation the closer it gets to the base mesh data (making the structure smoother, better fitting) depending if you are using a high resolution mesh or the base mesh necessity might vary

Other thing it will be used for is the water, and since the new water is not yet fully implemented there is also hardly a visible difference when setting it on the lowest setting.

 

The lowest setting btw sets the cfg with a nr "60" which is according to AMD`s limit settings in CCC or Radeonpro already a very high setting.

 

I think having Tesselation at 2x means the base polygon (think square) is divided into 4 polygons (2long,2wide) per set res distance and 4x means a polygon is cut to 16 pieces and so on. (so 60x is already an incredible amount of extra work for the GPU) 

I have a 660TI and have tessellation set to the extreme right. I get constant OOM errors. Others have told me this is not VRAM related - is this true? 

 

That is correct. In theory it is only exceeding VAS that should lead to an OOM. If you reach the limit of VRAM you will "only" have stutters and suffer graphical errors/glitches.

 

That said, I've managed to get decent performance in P3D after som fine tuning, and I use lots of shadows and medium tessalation with good results. VRAM usage is 1,3+1,4 GB, perfect for my GTX 580.

Quick question...I am not at my pc right now. I remember a tessellation checkbox in P3D, but where is the slider?

 

 

Quick question...I am not at my pc right now. I remember a tessellation checkbox in P3D, but where is the slider?

 

Settings > Display > Scenery > Tessellation Factor