Things you will need -:
* Photoshop or similar graphics editor
* A dds converter if your graphics package doesnt have one (I use dds2 converter which works a treat)
* Tanita's NWN2Packer off nwvault
* retexmdb a tool off the nwvault
1. First find the mdb (model file) and dds (diffuse map (unsuffixed), normal map (suffixed "_N"), glow map (suffixed "_I") and tint map (suffixed "_T") files) that correspond to the model you want to reskin. All placeables will have diffuse and normal maps but not all of them have glow and tint maps and I dont know how to add them, I suspect you'd need 3dsmax and some 3d modelling skill to do that which I dont have. You'll have to be content with changing what comes with your placeable for now.
For OC content -:
* the dds files are contained in C:/Program Files/Atari/Neverwinter Nights 2/Data/Materials.zip
* the mdb files are contained in C:/Program Files/Atari/Neverwinter Nights 2/Data/Models.zip
All other content is contained in the haks usually and you'll need nwn2packer to find what you need and export it. the mdb and dds files are usually similarly named so it should be easy to find what you are looking for.
Put your dds and mdb files in a separate folder for ease of use.
2. convert your dds files to psd files or anything that is suitable for editing in your graphics editing package.
3. open up your dds files in the graphics editing package (which I'll just call photoshop from now on to make it easy). In most instances your diffuse map will look similar to what you might see in the game, your normal map will look like an embossed version of the diffuse map, your glow map will look different depending on the placeable and your tint map will be a bright red, green and blue version of the diffuse map.
This is the most difficult part as some placeables use the diffuse map for the main texture (like the stained glass I played with), some use the normal map to add the main effects (like all the tavern sign placeables) and use a strange staged mishmash to get the 3d depth, others use the tint map to give the placeable its "look" in game (like a couple of the banner placeables).
I'll only deal with changes to the diffuse map as its the easiest to do.
4. Take your diffuse map and add to it, change what you will and save it under the name of the new placeable you want to create. retain the formatting. So if it is a new stained glass window for example you'll name it "PLC_WI_WINDXX" with xx being a unique number that hasnt been used anywhere in the haks before.
5. Next you'll make your normal map from your diffuse map. Use the emboss effect from photoshop. Next sharpen with the sharpen filter. Then go to the other normal map you already opened in photoshop and sample the colour with the eyedropper. I dont know if you need this or not but do it anyway.
6. Use the fill option in photoshop, increase the tolerance to 300+ and drop the opacity to about 60-70%. Drop in your colour on a bit with no texture and it should fill everything with the same colour but retain the normal map embossing.
7. Sharpen again just be on the safe side.
8. Save your work now as the same file name but at the suffix "_n" to the end of the filename so in my previous example with the stained glass diffuse map, make it "PLC_WI_WINDXX_n".
9. Tint maps I havent done much work with yet but as far as I can tell. the Red, Green and Blue colours correspond to the areas you can have as tint1, tint2 and tint3 in the toolset. Just use the eyedropper to grab the colours of the tint map you already opened in photoshop and use the drawing tools to draw the colours on where you want to be able to change them in game. save it with the suffix "_t" eg. "PLC_WI_WINDXX_t"
10. Glow maps.. I suggest just renaming the one that comes with the placeable you are reskinning or experimenting until you get the glow right. save it with the suffix "_I" eg. "PLC_WI_WINDXX_I"
11. Convert your new graphics files to dds now and place them in your NWN2 (My docs) override folder.
12. Change the name of your placeables mdb to correspond with the diffuse map file you created in photoshop and dumped in your override. Put your newly named mdb file in the same folder as your retextmdb tool (I suggest putting retexmdb in a folder on C: drive).
13. Open up the command line on your puter (Run "cmd") and follow the instructions that come with the retextmdb package. A note here, with your .materials file that is created, leave the top line the same and change all the indented diffuse, normal, glow and tint map references to the same file name as the dds files you just put in your override directory. you just run the retex tool once to get the materials file and then again to change the references in the mdb file. to make sure it has worked, check in detail view in the file folder to see when the mdb file was last changed.
14. Put your new mdb file in your override directory with its corresponding dds files.
15. Open up the alfa placeables.2da file. This is located in alfa_2da.hak and you'll need to export it using nwn2packer. Export it to your override directory and open it with with a text editor like wordpad.
16. Add a reference in the 2da file as close as possible to the placeable you just reskinned. Use the same formatting all across the line in the 2da and dont bugger anything up or it wont work. Save it with your changes, dont use "Save As".
17. Now open up the toolset in a blank unhakked module. make a new placeable blueprint, scroll through the appearances and you should see your new appearance in the list. Preview your placeable or put it in a new area to see it.
(Placeholder.. work in progress)