Bump maps

[CBris]

I have created bumpmaps using Corel and they worked fine. Greyscale image in 24 bit rgb format, save the red channel as alpha, floodfill red with black and blue with white, invert green and then open the coloured image in DXTBmp and add the previously saved red channel as alpha.

I understand the FSX convention - green channel and red channel for height info.

It all worked beautifully.

Something has happened, has been forgotten, I don't know what, but suddenly any bumpmaps I create seem to remove the smoothing from the model in FSX. Here's an original and a modified Texan cowling... (attachment). You can see othe two left hand images, that the cowling is smooth (uses the given bumpmaps) and the two righthand images are showing the facets around the front of the cowling.

Now I am getting myself all in a tizz

In Corel I exported the red channel as a separate bitmap to save as the alpha channel for later insertion into the dds via DXTBmp. It looked exactly like the way FSX bumpmaps look when opened in DXTBmp and ImageTool - a grey bitmap with a slightly shifted set of lines and rivets. The diffuse image is that typical blue hued image. It always used to work

I have recently installed both GIMP and Photoshop Elements - both support the nVidia normal map plugin (although PSE does not support alpha channels). But apparently you can't export these nVidia normal mapped images with an alpha channel - that is greyed out in the various options windows prior to saving. When I go to alpha channel in GIMP it is black and the help files go on about masking. The WIKI here simply says:

Because of the way the shaders have been written for FSX you can not use the normal map you just created directly. You will have to do some modifications to it. Failing to do so will result in a unrealistic view of your model.

Here are the steps you need to take:

Copy the content of the red channel to the alpha channel
Make the red channel black
Invert the green channel
Make the blue channel white

The image on the right shows the resulting normal map for FSX.

OK, Got all that and I can create my flattened 24bit greyscale texture, modify with the nVidia plugin... But HOW do I get the red channel into alpha? Whenever I try saving as dds, all that happens is that the purpley coloured image is saved and there is no alpha.

One of the programs must be affecting my diy bumpmaps so something has changed somewhen. I definitely could create bumps in the past without my method "killing" the model's smoothing. I have even successfully created different cube maps and I have even edited bump maps so that I even got multi-directional light and shade when the developer puts both sides of a fuselage on the same sheet, but flipped (aerosoft twotter rear fuselage for one, and the Cataline for another.

So to recap the main question - why are "self-made" bumpmaps now suddenly causing facetting on FS aircraft in sim? What's changed? What have I forgotten? Can I add alpha using Image Tool? (you can in DXTBmp)

OR is it something completely different that causes mdl smoothing to fail?

 

[CBris]

No one? So it really is a secret I am not supposed to know because I don't have the right handshake?

 

[hcornea]

Smoothing is an inherent property of the mdl, so it can't be broken by a normal map.

Poor smoothing may be shown up by a bump map, or perhaps vice-versa.

 

[Skip67]

CBris,

If I understand you correctly, what you need to do is this....
Create the basis of your Bump Map in your image editor (Gimp or PS), run the Nvidia plugin as you mentioned, the image will turn a light purple colour. Now save the image as is in psd format (do not vertically flip it). You now have a bump map but it's not ready for use in FSX , there is one more step...

You must run the new bitmap through ImageTool.exe, an image conversion tool that comes with the FSX SDK. The image will turn a blue colour and will be flipped vertically for you. There are a few steps to this but all the info is in the SDK documents. If you get stuck or need some help let me know, sometime ago I made a 'Help' document on this so I will send it to you if you need it.

Skip.

 

[hcornea]

But HOW do I get the red channel into alpha?

I kind of missed this bit in the text of your post (I blame my iPhone)

I don't use Coreldraw, but (like most people I suspect, Photoshop CS4)

In Photoshop, you can switch from a layer View to "Channel View" which show RGB channels, and allows you to add Alpha channels.

You can select the R channel, and copy it into a newly created Alpha channel, and so on.

I have no idea how to use CorelDraw. If others similarly don;t use this program it may explain the lack of response.

 

[arno]

Hi,

You could also use the texture converter inside my ModelConverterX tool. If you load an image saved as a normal normalmap, it can do the FS specific tricks for you.

 

[n4gix]

Chris, for whatever it is worth, I've never managed to get DXTBMP to generate acceptable DDS bitmaps.

I use either the nVidia tools directly, or Imagetool, or Arno's MCX program.