Guest Workshop: UV Mapping in Nifskope : by Lady N

[Lady_Nerevar]

UV Mapping in Nifskope

for neater, easier re-textures

by Lady Nerevar (09/30/10)

A UV map is a representation of your 3D object on flat space. Essentially, it takes each polygon (triangle of which the model is composed) flattens it, and lays it out on a picture. The UV map dictates how your texture will sit on the model.

Knowing how to change the UV map is a great asset when retexturing, since you will no longer be restricted to how Bethesda placed their textures. Nifskope's UV editor is sufficient for most operations. Lets get started!

For this tutorial I will be using the wizard robe mesh (clothes/wizard/shirt.nif). Open it in nifskope, right click the skirt, and select Texture> Export Template in the resulting menu. Change the file path to something easy to remember. The size setting determines the size of the texture – most Bethesda textures are 512x512, you might want to go higher if your texture is bigger. Note that it only exports square maps, so if your texture is rectangular you will have to resize it later.

This is the UV map of the bottom section of the robe. This map is pretty self explanatory, here is what it all corresponds to:

Smarty Says: Its often useful to make a bright color 'texture' if you don't know what part of the map corresponds to what section of the mesh. Just make sure you're saving it as a separate texture, the last thing you want is to accidentally overwrite your original.

Lets take another look at our map. While it worked perfectly for Bethesda's texture, making a retexture is hard due to the angles in the map. You would have to spend a lot of time trying to make your texture conform to the curves of the belt and flaps. If you chose to do some sort of pattern, it would end up distorted. In short, this map is horrible for rextextures. However, using Nifskope, we can straiten out all those curves and make retexturing a breeze.

This is my texture. Notice how I simplified the map, keeping items in the same relative locations but straitening any lines. We'll simply make the map match the texture.

Once again, open the robe in Nifskope and right click the bottom section. This time, select Texture > Edit UV. This will open another screen (the UV editor) with your texture and UV map. You can stretch the editor to make it as big as you need. You can also modify the colors used by going to Render > Settings > Colors. My foreground color (unselected vertexes and edges) are a bright yellow, and my highlight (selected vertexes/edges) is blue. This way, I can easily tell what I'm modifying.

Lets start with the belt. Left click and drag to make a box around the bottom row of vertexes (the little points) and let go to highlight them. Then, hover over the selected points (your cursor should change to the standard arrow mouse) and move them down to the bottom of the texture.

Repeating these steps, straiten out the rest of the points so that they form a narrow, strait strip. All horizontal lines should be horizontal and all verticals vertical. Here is how my map and texture looks after wards.

Not bad! However, the belt still does not take up the whole texture, which looks pretty crappy on the model. Select the all the points on the right hand side and drag them to the end of the texture. Similarly, select the ones on the left and drag them to the left.

Ah, much better. We can now see the whole texture on the belt. Lets move on to the short belt section on the left. Our map has it placed beside the large section, and you'll notice that I didn't put a belt texture there. Thats because we're going to be re-using the texture for the right.

If you zoom out in the UV editor, you will notice that the main texture space is surrounded by more copies of your texture. This is to show the maping of large objects, such as buildings, in which the texture repeats (“tilesâ€) within the object. We can also use it to our advantage to re-use the same space for multiple objects.

Highlight the small belt section and move it to the texture on the top (it will be dimmed). Then, highlight individual point sections, straiten, and position just like before. This time you don't want to go to the very top of the strip, as that would result in the long texture being smooshed into the small mesh. You can however reduce some of the texture stretching by lengthening the map. Here is the fixed belt, and the new map:

The rest of the mesh follows the same principals: select nodes, straiten out based on texture. You should always look at your model as you're working to make sure that your edits look good.

For the middle belt, we are going to position the middle points on the brocade belt. Select the top two points and love them down and over, then do the same to the bottom two. I then straitened out the verticals and adjusted the horizontals slightly. Fixing the belt buckle is even easier – simply select the points that are outside your new buckle and move them inwards. The belt now realistically wraps around the robe's waist.

On the skirt, the row of closely packed points marks the beginning of the overlay cloth (white). Select the three outermost points and move them so that the 2nd row of points from the edge is at the end of the white cloth. I also pulled down and straitened out the top edge. If you need to select multiple points that are not adjacent to each other, you can hold down shift and click-and-drag to select.

After fixing the edges, I noticed some texture stretching along the sides. Because we moved the outer 3 points inward, the first polygon of the cloth was compressed. Because the polygon is smaller on the map then it is on the model, the texture comes out stretched. The only way to fix this is to make the polygon bigger on the map. In this case, I chose to move the points right of it to the right.

All that remains are the bottom of the skirt flap and pants. These are simple – just move the edge nearest to the edge downwards to match.

Here is the final product:

I hope you found this tutorial useful, and look forward to seeing what sorts of uniquely textured objects you come up with

[DarkRider]

Very nice Lady thanks for sharing! I've added this to our library here as well

[InsanitySorrow]

I already read it , But I think it's a great addition

[StarX]

Yup, good tutorial, Lady N!