Texture sheet, how to build one?

[riccardo74]

Hy guys I'm trying to build some object (basic) with Sketchup and import in FSX. All works fine but now .i want to master the texture sheet.

I read the great tutorial by Arno on .how to build your house but technically I can't understand how to build phisically the texture sheet, which program May I use, gimp, photoshop or similar. Any particular extension?

If you have any suggested tutorial it's very appreciated, thanks so much

Riccardo

 

[arno]

Hi,

The main tool to use is a graphics program like GIMP or Photoship indeed. You don't need any special plugins, it's typically a matter of taking pieces of photos and than editing them till they look fine on your texture sheet. In my tutorial I used GIMP, but any graphcs tool will provide the functions needed.

To make the texture mapping easier, I prefer to give each part in the texture sheet sizes that are a power of two (so for example 521x128 for the front of the building). That also gives best results with mipmaps.

 

[riccardo74]

Thanks Arno, so if well understand I have to create a new blank document and draw a square of the dimesions of specific resolution (calculated with your formula) for every texture, is it correct?

 

[Anthony31]

There are a few things to remember with texture sheets.

1. The dimensions must be a power of 2. So 1024x1024 pixels or 512x256 or 32x128 etc etc. The easiest thing to do with scenery is just work with 1024x1024 textures. Larger textures are not recommended as they may require the user to have the MAX_TEXTURE_SIZE=4096 line in their FSX.cfg file. Whatever paint program you use create a new image and set the size to 1024x1024 pixels (make sure it is pixels and not some other unit of measurement).

2. Use the export function of your paint program to save it as a 24bit BMP format file for use in your modelling program and in your BMP to DDS conversions. I know that some programs can use JPG or other formats but at some point you have to convert the texture to a DDS format and it's just easier if you use BMP to do this. Save the working file in the paint programs native format. This will keep any layers you create intact. If you need to make changes to the texture you can then edit the native format texture rather than the BMP. For organisational reasons I like to keep native format and BMP files in the same folder and this is right next to the folder I save the 3D models in (but not in the same folder).

3. Use unique names for your textures. Saving it as concrete.bmp might well lead to problems in the future. Something like ICAO_concrete.bmp is better where ICAO is the airport code. Something like RIC_ICAO_concrete.BMP is even better as it lets people know your name is associated with that texture.

4. One texture sheet itself can contain textures for multiple different models. If you can try to ensure that each model is using no more than 1 texture. This will ensure that there is the minimum number of drawcalls in your scenery.

5. Finally, to see the texture in FSX you must convert the BMP to a DDS file and place the DDS file into the texture folder for your scenery. This can be done with the DXTBMP program or Microsofts own Imagetool.

And now for some tips:

It is not necessary for the backs of any hangars to be the same resolution as the front. You can make the front of a hangar 1024 pixels wide while the back, sides and roof need only be 512 pixels wide. This means you are not wasting resolution and draw time on stuff that is not in the user direct line of sight.

Also, figure out what resolution you want to use. A small airfield you can have hangars with 1024 pixels wide. Using that sort of resolution 1 hangar could take up a whole 1024x1024 texture sheet. A large airport and you may drop it down to 512 or 341 (1/3 of 1024) or even 256 pixels and you could fit 4,9 or 16 hangars onto one sheet.

You can use any paint program (I use Corel Paintshoppro which is a cheaper alternative to photoshop) but I would definitely recommend one with a "perspective correction tool" especially if you are working with your own pictures. Or any pictures really. This tool lets you put four corners onto a photo and then click apply and it will magically square up the photo which makes it really easy to square up building shots.

 

[arno]

To add to the good suggestions above, don't use too different resolutions on one building from the same texture sheet. Because that can confuse the rendering engine when selecting the mipmaps and can result in not the highest mipmap being shown when it should (so blurry textures).

 

[riccardo74]

Guys you are great! Thanks so much for your help, very appreciated!

 

[lionheart]

Also, figure out what resolution you want to use. A small airfield you can have hangars with 1024 pixels wide. Using that sort of resolution 1 hangar could take up a whole 1024x1024 texture sheet. A large airport and you may drop it down to 512 or 341 (1/3 of 1024) or even 256 pixels and you could fit 4,9 or 16 hangars onto one sheet.

Anthony, I do not think 341 will work in FS. Only 64,128,256,512,1024,2048, and 4096. (In FS9, the highest is 1024, and you can do 32bit).

Riccardo, just learn how to pack your textures in there well. The art of stacking and arranging. I usually have the very large objects taking up the most room (fuselage, wings, seats, panel), and then small parts fit in all the nooks and crannys. If you study the stock Microsoft planes textures, you will see how well you can really cram things into a single sheet. If you want detail of a texture to show, it will need to be larger on a sheet.

If you have Max, you can take all the objects that will be on one sheet, select them, add a UVW UNwrap to them, go into the Editor, and arrange their mesh locations on the sheet, then 'Create Template' and that will be your starting bottom layer in Photoshop.

 

[Anthony31]

I just meant that with 341 pixels that you could put 3 textures side by side across one 1024x1024 texture.

 

[lionheart]

Ahh... Roger that. Good thinking. One can also shift the dimensions, speaking of that. 512x1024, 128x256, etc.

 

[gayanll]

I read the great tutorial by Arno on .how to build your house but technically I can't understand how to build phisically the texture sheet, which program May I use, gimp, photoshop or similar. Any particular extension?

Where is Arno's Tutorial?

 

[arno]

Build your house using SketchUp - FSDeveloper Wiki

www.fsdeveloper.com