Blendmask

hefy_jefy · Post by **hefy_jefy** » Sun Oct 07, 2007 10:18 am

I have been making some blended photoscenery using a custom blend mask, I have been successful but there are a couple of problems:

Note these are not just thin rectangular blend masks but have large black areas.

I followed the instruction to create a greyscale .TIF image with the same name as the photo scenery but added _B as instructed - this almost worked. The multi source .INF file was created and it compiles without errors. However when viewing the resulting BGL file in TMFviewer the whole of the black area shows up black. After some headscratching I figured that I didn't need the NullValue = 255,255,255 statement and removed it from the .INF file. Now dropping the .INF directly onto resample.exe worked and with a little tweaking things are starting to look good.

I have one very strange effect, at some places at the edge of every image so far created I see red/yellow areas. I can see no reason for this except that they seem to occur where the shape of the mask is concave - anybody else seen this?

Geoff

luisfeliztirado · Post by **luisfeliztirado** » Sun Oct 07, 2007 11:27 am

Hello Geoff,

Have you seen this thread on making custom ground textures?

http://www.ptsim.com/forum/topic.asp?TOPIC_ID=1060

Best regards.

Luis

hefy_jefy · Post by **hefy_jefy** » Sun Oct 07, 2007 9:57 pm

Hi Luis,

Yes indeed this is where I found out how to create the TIF with the _B in the filename. But I wonder if I am going about this in the wrong way? Here are the steps:

1. Create a .bmp map file using the option Add Map>From background.
2. Edit this .bmp creating white areas where I need transparency and save.
3. Create a blendmask (256 greyscale TIF) from this edited image, and name it the same as the original image but with the _B added. (Incidentally either LZW or Uncompressed seem to work)
4. Rename the .INF file to be the same as the image name and drop it on resample.exe (this is where it was going wrong until I removed the NullValue statement.)

I just spotted the information about the compression quality; I am going to try different settings because the new BGLs created are much larger than the ones without the blendmask...

I have a feeling I am missing something here, but not quite sure what!

Geoff

Luis Sa · Post by **Luis Sa** » Mon Oct 08, 2007 2:55 am

Hi Geoff,

I would not make changes in the 1st bmp except if I need a color match to the existing default landclass (there is a programme that can do that very efficiently which minimizes the need for the blend mask). May be I would check if there is no pure white in this image so that I can live with the NullValue (which has been reported to cause some problems). Then I would make a copy of the 1st .bmp and I would give it a name of ._B. I would save it as 256 B&W with the TIF format.

Here is the code that SBuilderX uses to determine if there is a blend or water mask job:

Code: Select all

       Dim IsBlend As Boolean = False
        Dim IsWater As Boolean = False
        Dim BlendName As String = Path.GetFileNameWithoutExtension(Maps(N).BMPSu) & "_B.TIF"
        Dim WaterName As String = Path.GetFileNameWithoutExtension(Maps(N).BMPSu) & "_W.TIF"

        If File.Exists(My.Application.Info.DirectoryPath & "\tools\work\" & BlendName) Then
            IsBlend = True
        End If

        If File.Exists(My.Application.Info.DirectoryPath & "\tools\work\" & WaterName) Then
            IsWater = True
        End If

If the blend mask only has shades of gray I found that white zone shows will show my 1st .BMP and black zones will show the default. In the Tools/Bmps folder you will find a blendmask.tif file that SBulderX uses to create a photo BGL from the background with a single click. You will see black around the borders and a transition to the main white zone.

Kind Regards,

Luis

luisfeliztirado · Post by **luisfeliztirado** » Mon Oct 08, 2007 1:03 pm

Hello Geoff,

In that thread, I added a section on blend masks and null values, and how mixing the two will give strange results (black borders, or red areas). This explanation is towards the end of the thread, and may help to explain what you are getting.

Best regards.

Luis

hefy_jefy · Post by **hefy_jefy** » Wed Oct 10, 2007 3:35 am

Hi Luis,

Many thanks your additional information corresponds exactly with what I am seeing! I am now experimenting to see if I can reproduce the strange red/yellow artifacts; that I see at one or two places around the edges. I think it may be due to an imperfect fit between the various images...

One thing I have found is that reducing the quality to 50% has hardly any discernible effect on the appearance in FSX but reduces the size of the BGL file by about 70%. However this may be more noticable on higher resolution images - I will see.

Thanks again

Geoff