This is a rambling post about the FSX land detail texture as couple of issues have come up of late. Basically I wanted to explain what the detail texture is and why it matters.
As you fly around in FSX the resolution of the ground textures look good at altitude but as you descend lower the resolution become increasingly apparent. This is not such an issue if you land at a detailed airport which has its own detailed textures, but if you land at a grass strip the low resolution will become apparent.
Now FSX has amelioration for this – the land detail texture. This is best described as a light film grain which is blended with the ground textures to mask the worst of the pixilation.
FSX allows you to turn this detail textures on or off in the settings menu.
This is what grass looks like with the detail turned off
The detail texture masks this and greatly improves matters.
At altitude the base texture resolution is sufficient and so the detail texture is less important. When using higher quality textures such as Orbx the detail is even less important at altitude.
There are various replacement land detail textures which are often described as HD grass. I was planning to write a blog post with lots of pictures about them but then I found a well written and presented article on another blog by Wojciech Przybylski – so instead of duplicating it I suggest that you follow this link and then come back for some further commentary from me!
Hopefully you found that interesting.
One thing to empathize is that the detail texture is used everywhere that is not
- a building or
- a detailed airport.
It is used for sand, snow, glaciers, rock, roads and parking lots. So in this scene here
If we examine the ploughed field and road at the top right
With Drzewiecki Design Grass you can see a faint grid. Note when I upload this post I worry that this will be too compressed.
With default detail1 – this is much less pronounced.
Snow with Drzewiecki Design Grass. Nb I know that they include a separate snow texture – this is an example of how a detailed grass texture looks with snow
Snow with default detail1.bmp
As Wojciech has identified the FTX Aero detail textures are much better in this regard and do not exhibit the grid effect.
DX10 and Detail Textures
For the most part land detail textures behave exactly the same in DX10 as in DX9. The exception to this is if the land detail texture does not have mipmaps. There is at least one freeware grass texture that is not mipmapped.
I do not however know exactly where it comes from, I was contacted by a customer who had downloaded it from a YouTube FSX channel link. The majority of HD grass textures such as Drzewiecki Design Grass are mipmapped.
The way that DX10 handles missing mipmaps is different to DX9 (the minification algorithm is different) and this resulted in a very poor shimming/grain effect.
I have added into the DX10 SceneryFixer Diagnostics a specific check for this texture. If it is found then the following warning message is produced
WARNING! Non standard scenery\\world\\texture\\detail1.bmp with no mipmaps – terrain will badly shimmer/look grainy.
If you get this message then you should switch to an alternative detail texture.
As there may be other detail textures of different sizes without mipmaps – I also added in a further check which tested if the texture was standard or not. This produces the following message:
BE AWARE! Non standard scenery\\world\\texture\\detail1.bmp – if this doesn’t have mipmaps terrain will badly shimmer/look grainy.
This was intended as information for me when I received support calls. No action is necessary as most replacement detail textures are mipmapped and work ok. Unfortunately some people have been alarmed by this message and so I have now removed this test from further DX10SceneryFixer purchases.
DX10 Limit Detail
In 2.11 I added a new option Limit Terrain Detail
The intention was to assist people who want to use a detailed grass texture by disabling the use of the detail texture for scenery more than 500m away. This then acts as if the Land Details option in FSX is turned off. The idea was that when at the grass strip you would see the detailed grass but then as you gained altitude the grid effect would be eliminated.
I have noticed that the transition is noticeable on snow and in some circumstances you see a disk on the ground. I will revisit this in the next release and handle the transition better.