MIPMAP and other settings for graphics

[jin_xi]

Hi all,

after hearing complaints about noisy textures and similar stuff i tried some experimenting. To try it yourself you need to edit source files and compile minetest afresh. here are the changes:

for mipmapping change main.cpp as follows:

change line 1296 to the following:

// Disable mipmaps (because some of them look ugly)
driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, true);

please report if you find anything "ugly"

for anisotropic and / or bilinear filtering, change clientmap.cpp as follows:

after line 469 insert this:

buf->getMaterial().setFlag(video::EMF_BILINEAR_FILTER, true);
buf->getMaterial().setFlag(video::EMF_ANISOTROPIC_FILTER, true);

have fun hacking!

[VanessaE]

On my system, adding the mipmap and anisotropic filtering festures as directed above makes a world of difference in the game (I tried it in 0.4.1 and 0.4.2-git from a day or two ago), and has no performance penalty whatsoever.

Note that you should only use the bilinear filter if you're using exclusively higher-resolution textures - anything in the 16px range will turn blurry with bi- or tri-linear filtering. High-resolution textures just get smoother.

I recommend the above settings be attached to checkboxes in the GUI. One each for mip-map and anisotropic filtering, and a radio button to switch between no-, bi- or tri-linear filtering. These are must-have's!

[Calinou]

I recommend the above settings be attached to checkboxes in the GUI. One each for mip-map and anisotropic filtering, and a radio button to switch between no-, bi- or tri-linear filtering. These are must-have's!

+1, maybe an ability to change GL texture mode in minetest.conf would be good too.

[rubenwardy]

...and a radio button to switch between no-, bi- or tri-linear filtering.!

Or a drop-down-list :)

[glomie]

Your change make texture blured.

[rubenwardy]

Your change make texture blured.

That is the point.

AF is aperture, which is what the eye uses to focus

iirc it is a type of primitive shading, that can be used on old machines w/o shaders

[VanessaE]

I would also recommend that a threshold setting be added for the bi-/trilinear filtering options - that is, a setting that says "only apply this filter if the texture is larger than this resolution". That way, high-resolution textures get the full-blown filtering, while low-resolution textures don't get the bi-/trilinear filtering, so they don't get blurry.

[leo_rockway]

Your change make texture blured.

That makes the highres textures don't look bad in the distance.
I tried this with lowres textures and it looks terrible, but with highres it's very necessary. Hence, the GUI to pick what you want would be ideal.

EDIT: MIPMAP +1

EDIT2: Here are screenshots of mipmap:

With mipmap:


Without mipmap:



Compare the trees on the background on the left: with mipmap they look better, IMO. The papyrus in the background looks bad with mipmap, though (it kind of disappears). These screenshots only have mipmap true/false. I didn't add AF, BI, TRI, because they make the default texture look terrible on my box.

[VanessaE]

Screenshot from my texture pack test track, using a build with AF/MM/trilinear turned on:


(2550x1985 pixels, download and load it into a proper image viewer to see it full size, or maybe right click, view image, and click again if you're using firefox)

[VanessaE]

C55 clarified the meaning of the "ugly" comment:

-----
[08-27 08:04] <celeron55> the problem with mipmaps is when you use them at the regular 16x textures
[08-27 08:04] <celeron55> they start to downscale the resolution too early
[08-27 08:04] <celeron55> you can see "borders" at where the scaling changes
[08-27 08:04] <celeron55> try rails for example
[08-27 08:05] <celeron55> (because they have clear single pixel detail)
[08-27 08:05] <celeron55> that is what the ugly refers to; and it was not initiated by me but rather somebody else and i just threw the code in
[08-27 08:05] <VanessaE> however, that isn't happening with AF+MM alone, at least on my box. Add in bi-/tri-linear filtering and it does.
[08-27 08:06] <celeron55> go blame whoever that was
[08-27 08:06] <VanessaE> not blaming you :-) just trying to understand the comment :-)
-----

Also, the following info may be useful:

-----
[08-27 08:14] <Calinou> "you can see "borders" at where the scaling changes" < and this is why we have linear mipmapping
[08-27 08:14] <Calinou> minetest used "nearest" mipmapping prior to 0.3; the mipmapping can be smoothed by using "linear" mipmapping
[08-27 08:15] <celeron55> i guess that is the default of irrlicht
[08-27 08:16] <VanessaE> celeron55: also, on my system, fwiw, AF+MM, with or without bi-/trilinear has no effect on performance.
-----

Also, as a side note: on my system, linear or something better apparently is the default - I don't see any hard borders between the mipmap levels.

[leo_rockway]

C55 clarified the meaning of the "ugly" comment:

-----
[08-27 08:04] <celeron55> the problem with mipmaps is when you use them at the regular 16x textures
[08-27 08:04] <celeron55> they start to downscale the resolution too early
[08-27 08:04] <celeron55> you can see "borders" at where the scaling changes

I guess this is why the papyrus disappears. Also, hard borders are what looks so bad about AF/BI/TRI in 16x (the blurriness, is bad, the hard borders are what make them unbearable). I should post a screenshot of the hard borders...

[VanessaE]

My official proposal (summary of my previous posts):

We already have code at the top of this thread and I've provided Ubuntu AMD64 builds that use those changes successfully, with zero issues on my system anyway.

The following should be added to the "Settings" menu, since there are already some performance-related settings found there as it is.

• Checkbox to turn on Anisotropic Filtering.
• Checkbox to turn on Mip-Mapping.
• Dropdown to set the Anisotropic filtering type from whatever types Irrlicht supports (e.g. Nearest Neighbor, Linear, etc.).
• Dropdown to turn on/off extra Bilinear or Trilinear filtering apart from the other settings above.
• Dropdown or Slider to set the resolution above which Bilinear/Trilinear is applied (anything below should be drawn without the extra filter).
• Checkbox to set whether or not the extra filter should apply to transparent objects.

All of these should default to "off", that is set so that the game behaves as if it's unchanged. All of these settings are supported by Irrlicht from what I've been looking at. There's lots of empty space to the right in the "Settings" menu, so just dump it all there in some reasonable order.

[Calinou]

C55 clarified the meaning of the "ugly" comment:

-----
[08-27 08:04] <celeron55> the problem with mipmaps is when you use them at the regular 16x textures
[08-27 08:04] <celeron55> they start to downscale the resolution too early
[08-27 08:04] <celeron55> you can see "borders" at where the scaling changes

I guess this is why the papyrus disappears. Also, hard borders are what looks so bad about AF/BI/TRI in 16x (the blurriness, is bad, the hard borders are what make them unbearable). I should post a screenshot of the hard borders...

Linear mipmapping doesn't have these hard borders (see Optifine mod for Minecraft; "Nearest" mipmapping has, "Linear" hasn't).

[sfan5]

On my system, adding the mipmap and anisotropic filtering festures as directed above makes a world of difference in the game (I tried it in 0.4.1 and 0.4.2-git from a day or two ago), and has no performance penalty whatsoever.

Note that you should only use the bilinear filter if you're using exclusively higher-resolution textures - anything in the 16px range will turn blurry with bi- or tri-linear filtering. High-resolution textures just get smoother.

I recommend the above settings be attached to checkboxes in the GUI. One each for mip-map and anisotropic filtering, and a radio button to switch between no-, bi- or tri-linear filtering. These are must-have's!

+1

[sdzen]

finally i can use nosferatu HD texture pack again

[leo_rockway]

C55 clarified the meaning of the "ugly" comment:

-----
[08-27 08:04] <celeron55> the problem with mipmaps is when you use them at the regular 16x textures
[08-27 08:04] <celeron55> they start to downscale the resolution too early
[08-27 08:04] <celeron55> you can see "borders" at where the scaling changes

I guess this is why the papyrus disappears. Also, hard borders are what looks so bad about AF/BI/TRI in 16x (the blurriness, is bad, the hard borders are what make them unbearable). I should post a screenshot of the hard borders...

Linear mipmapping doesn't have these hard borders (see Optifine mod for Minecraft; "Nearest" mipmapping has, "Linear" hasn't).

Yes, the mipmapping didn't show hard borders, it was AF/BI/TRI that showed very obvious hard borders.

[PilzAdam]

after line 469 insert this:

buf->getMaterial().setFlag(video::EMF_BILINEAR_FILTER, true);
buf->getMaterial().setFlag(video::EMF_ANISOTROPIC_FILTER, true);

Its after line 546 in latest git (i think).

[RealBadAngel]

can some1 make windows build with it?

[VanessaE]

I have put the basics of the above discussion into the engine with a proper GUI to control the settings, and have released a patch and build for Ubuntu Linux, plus sfan5 has released a build for Windows. I figured that deserves a new thread, since more stuff is likely to be added in the future, so go here:

http://minetest.net/forum/viewtopic.php?id=3410

Enjoy!