DDS textures needs more than 3 Mip Maps

[zaelu]

Hello

 

I noticed the Mig21 model in DCS 1.2.9 has some small shimmering effects on the external texture when view from bit away (when the last MipMap is used).

 

One can notice it very easy if the plane is rolling on the tarmac and viewer is looking so he sees the cockpit. Inside it will be a bunch of dancing pixels. Or also rolling on the tarmac press F3 and wait to see the plane pass by and you will notice the lines on the skin dancing and shimmering.

On the Northeria skin there are some white speckles of wear on the plane paint and those white spots dance a lot when view from bit far and while the plane is moving in respect with the camera.

 

Solutions to this are these:

 

1. Make more than 3 Mips. The difference in size is not semnificative... 200kb max

2. Use DTX 5 for all textures! DTX1 and 3 render worse results. I'm thinking that's why you decided to cut the Mips to 3 because using DTX1 or DTX3 on the ones with transparency did not gave you much difference (although there is) with using more Mips.

 

I can post here my modified files (aprox 200Mb archive) if Letherneck Simulation staff allows it. I will upload the modified files to DCS site once the Mig21Bis section is up.

 

dds dtx5 are larger files but I see no loss in framerate with them and the increase in quality of render is visible even if the resave comes from a dtx1/3 file. It seems that newer video cards/drivers treat better the dtx5 textures. I am sure that saving the template files directly would get better results.

 

You can see here default:

 

 

 

And here modified dds

 

 

 

I'll try to add a video but my upload speeds are laughable here.

 

besides the 2 livery folders I modified these textures in 3 archives. The ones that remained were left dtx 1 or 3 but had more than 3 mipmaps.

Edited July 29, 2014 by zaelu

[Cobra847]

Thanks for the post! The shimmering is a known issue and remained unfixed for most of the liveries/textures due to other pressing issues.

 

We have now adjusted all MIPs for external textures. The issue has not been the amount of mipmaps, but is actually caused by a sharpening algorithm set in the DDS plugin. :)

We use sharpening for cockpit textures as their MIP levels kick in far quicker -- but we did not turn it off for some of the external textures.

 

Thus, shimmering when not using adequate AA/AF, especially since the main textures are at 4K at the moment.

 

We'll take a look at DXT5 vs DXT1 results, however -- the compression of DXT1 is fairly efficient and has, so far, had negligible quality differences.

We're wary of utilizing too much VRAM (The MiG-21 is already quite heavy in that respect).

 

Cheers!

Nick

Edited July 29, 2014 by Cobra847

[GeorgeLKMT]

Heh, I actually complaned about the similar thing a few days ago, but with cockpit textures

 

Although I'm personally still not sure about the DXT1 vs DXT5 thing. I heard a lot of people saying how DXT5 is better (rgb-wise, not alpha), but common sense actually says otherwise, since DXT1 has better compression ratio (because of no alpha or 1bit alpha only) and therefore smaller files. And I struggle to find any actual proof that DXT5 has indeed better performace or quality, when the compression algorithm appears to be the same.

[Cobra847]

Heh, I actually complaned about the similar thing a few days ago, but with cockpit textures

 

Although I'm personally still not sure about the DXT1 vs DXT5 thing. I heard a lot of people saying how DXT5 is better (rgb-wise, not alpha), but common sense actually says otherwise, since DXT1 has better compression ratio (because of no alpha or 1bit alpha only) and therefore smaller files. And I struggle to find any actual proof that DXT5 has indeed better performace or quality, when the compression algorithm appears to be the same.

 

MipMaps in the cockpit have certainly been a subject of much testing here. I settled on the default filtering with a Sharpen Medium preset, which yields decent results in terms of shimmering vs quality loss (i.e. blurriness at distance).

It's difficult to cater to every single configuration, and obviously those without any AA will always see some artifacting, but at 4X (with no TSAA) things look decent on my end.

 

In the end, we can always publish some alternate textures with different filtering/sharpening combinations as optional patches.

 

DXT compression is fairly robust, but considering most textures don't need the Alpha, DXT1 has been the format of choice so far.

Interestingally, the unique colour palette of Normalmaps makes DXT1/5 completely useless though.

[zaelu]

Hello Nick.

 

Thanks for reply. From what I've seen and understood, the problem is the fact that after the smallest of 3 Mips is used that texture is resized without any filtering (resampling) no matter the AF set in the driver. The texture it self is shimmered by this resize and no AF could save it and the movement of camera makes it worse. It is true that the texture appears more sharper but I think that is a side effect.

 

Have you noticed that having the textures as TGA make the driver either create mips or filter nicely the texture that no jaggies or shimmering appear. True... the texture is huge then :) .

 

Heh, I actually complaned about the similar thing a few days ago, but with cockpit textures

 

Although I'm personally still not sure about the DXT1 vs DXT5 thing. I heard a lot of people saying how DXT5 is better (rgb-wise, not alpha), but common sense actually says otherwise, since DXT1 has better compression ratio (because of no alpha or 1bit alpha only) and therefore smaller files. And I struggle to find any actual proof that DXT5 has indeed better performace or quality, when the compression algorithm appears to be the same.

 

I was building a thread about it on that forum. I'll respond to your thread.

 

Is the same issue and I also fixed it the same way.

[Cobra847]

Hello Nick.

 

Thanks for reply. From what I've seen and understood, the problem is the fact that after the smallest of 3 Mips is used that texture is resized without any filtering (resampling) no matter the AF set in the driver. The texture it self is shimmered by this resize and no AF could save it and the movement of camera makes it worse. It is true that the texture appears more sharper but I think that is a side effect.

 

Have you noticed that having the textures as TGA make the driver either create mips or filter nicely the texture that no jaggies or shimmering appear. True... the texture is huge then :) .

 

 

 

I was building a thread about it on that forum. I'll respond to your thread.

 

Is the same issue and I also fixed it the same way.

 

Hi Zaelu,

 

As noted, the issue with our textures is primarily not due to mipmap levels, but rather the sharpening setting we use.

In order for Mipmaps to appear sharper in the cockpit, we sharpen each level. This setting was incorrectly left on for the exterior textures too. :)

 

I'll take a look at increasing the number of mipmap levels per your suggestion as well, however. Thanks!

Edited July 29, 2014 by Cobra847

[GeorgeLKMT]

I'll take a look at increasing the number of mipmap levels per your suggestion as well, however. Thanks!

 

Please do that :) I just generated all mipmap levels and marked them 0,1,2,3,4... right on the texture just to see which level kicks in when, and looking from the side while the model is spanning across the whole screen (1920px width), third MIP level is already displayed, but your textures seems to have only two levels at the moment. ;) And thanks for acknowledging this issue, everybody hates shimmering! :P

[Kuky]

Please do that :) I just generated all mipmap levels and marked them 0,1,2,3,4... right on the texture just to see which level kicks in when, and looking from the side while the model is spanning across the whole screen (1920px width), third MIP level is already displayed, but your textures seems to have only two levels at the moment. ;) And thanks for acknowledging this issue, everybody hates shimmering! :P

I hates shimmering :smilewink: