Basic textures in GIMP: Wrinkles

Overview

This tutorial shows how to add some wrinkles to your texture (to simulate wrinkles in clothes) using GIMP.

This tutorial assumes that you already have a mesh and a UV map created for it (see Adding a UV map for more information about how to create a UV map for your mesh).

Required tools

• Blender
• GIMP

Adding wrinkles to your texture

Mark the wrinkles in Blender

Texture settings in Blender

Marking the wrinkles position in Blender

Even though you have the UV map layout as a guide, sometimes it is difficult to now where to paint the wrinkles by only looking at it. I find it very useful to draw first a picture in Blender on which I mark the places where I want to paint them, and then use this as a map in GIMP. To do this:

1. Open your mesh in Blender and subdivide the screen in two: on the right side of the screen leave your mesh and on the left side open the UV map screen (see Adding a UV map for more information).
2. Select the Textured Draw mode for your mesh and add a new white image as a texture as shown in picture Texture settings in Blender.
3. Go to Texture paint mode for your mesh. You can set the brush colour, intensity and other parameters on the Paint section, as shown in picture Marking the wrinkles position in Blender.
4. In Texture paint mode, the cursor has turned into a brush. Paint directly on the mesh with it to mark the places where the wrinkles should be. You'll see that each time you draw a line on your mesh, you are drawing the same line on the image that's on the left side of the screen as shown in picture Marking the wrinkles position in Blender. Don't worry if don't they look too well: you are only marking the places where the wrinkles should be, not drawing them (the actual drwaing wil lbe done in GIMP).
5. Once you've finished marking the wrinkles, save the image you've painted by selecting the menu option of the left side of the screen Image -> Save as. Select the folder and enter the name of the file where you want to save this image and press OK.

Edit the wrinkles map in GIMP

Deleting the background colour

Now we are going to edit a little the image we've previously created in Blender:

1. Open in GIMP the image that contains the wrinkles map
2. Select the menu option Colors -> Color to Alpha
3. On the window that will pop up select the background colour of your image as the colour to be turned into alpha (in the example, the background colour is white), as shown in picture Deleting the background colour and press the OK button.
4. Now your wrinkles map will contain only the wrinkles painted in black and the rest of the picture will be transparent. Save this image.

Paint the wrinkles in GIMP

Paintbrush settings

Adding Gaussian Blur

Painted wrinkles

The next step is to paint the actual wrinkles on the texture:

1. Open your base texture in GIMP (for this tutorial I am going to use the Cloth texture explaind here Basic textures in GIMP: Cloth as the base texture but you can use any texture as a base).
2. Copy the wrinkles map as a new layer on top of your base texture:
   1. Open the image with the wrinkles map in GIMP
   2. Select the menu option Edit -> Copy
   3. Go to the GIMP instance where yout base texture is and select the menu option Edit -> Paste as and select New Layer from the drow down menu.
3. Now add a new transparent layer on top of the wrinkles map. This is the layer where we are going to paint the wrinkles:
4. Select the menu option Layer -> New Layer
5. Add a name for the new layer, select Transparency on the pop-up window and click OK

   Note: To see and work with the different layers that you have in your image:

   • Select the menu option Windows -> Dockable Dialogs -> Layers '
   • This will open a window with the layers stack for your image as the one shown in picture Layers stack'
     • To work on one of the layers, select the corresponding layer in the stack and then work in GIMP main edition window: all you do (painting, erasing, resizing, etc) will be done on the selected layer.
     • To hide/show one of the layers, click on the eye icon at the left of each of the layers in the layer stack.

6. Select the Paintbrush tool from the toolbox and:
   1. Select white as the painting colour.
   2. Select one of the Circle fuzzy brushes available to paint the wrinkles.
   3. Check the Fade out box as shown in picture Paintbrush settings.
   4. The size of the brush will depend on the size of the wrinles you want to pay. Adjust it as required.
7. Select the new transparent layer in the layers stack and begin drawing lines on it to represent the wrinkles using the wrinkles map you draw in Blender as a guide.

   Tips:

   • In order that the wrinkles look more natural, draw fat lines and thin lines between the big ones and, draw lines of diferent lenghts. Also don't draw straight lines, give them instead a slight curve.
   • I usually set the opacity of the wrinkles map layer to 50. This way I still can use it as a guide but it doesn't hide the wrinkles I am drawing.

8. Once you are done painting the wrinkles, add some blur to them:
   1. Select the menu option Filters -> Blur -> Gaussian Blur
   2. Set the blur radius to 10 as shown in picture Adding Gaussian Blur (you can play with different values for the radius and see which one fulfills your requierments).

Now, you can delete the wrinkles map layer as it was only a guide to paint the actual wrinkles. After that, your texture will look somthing similar to the one shown in picture Painted wrinkles.

Add volume to the wrinkles

Bump map window

The next step is to add volume to the wrinkles you have just painted. For doing this we are going to use the Bump map technique explained here: Giving sense of volume to textures using GIMP.

1. Select your base texture in the layer stack (the Cloth texture in this tutorial)
2. Select the menu option Filters -> Map -> Bump Map
3. A window like the one shown in picture Bump map window wil pop up
   1. In the Bump map box, at the top, select the layer that contains the wrinkles you've painted.
   2. You can change the values of the properties, and see how if affects the original texture in the Preview window (check the Preview box to see this changes). For wrinkles, I find that the Sinusoidal map type gives better results, but you can try the other values and see which one looks best for you.
   3. Once you've got the results you want, click OK.

Make the base texture follow the wrinkles

Displace map window

Final texture with wrinkles

The last step is to make the base texture bend with the wrinkles. For getting this effect:

1. Select your base texture in the layer stack
2. Select the menu option Filters -> Map -> Displace
3. A window like the one shown in picture Displace map window will pop up:
   1. Select the wrinkles layer in the X and Y boxes
   2. Set the X and Y displacement to -5 (again, you can try other values and see which one looks better to you).
   3. Once you've got the results you want, click OK.

As a final touch, to increase the effect of relief of the wrinkles:

1. In the layer stack, select the layer that contains the wrinkles and change the layer mode from Normal to Soft Light, and the Opacity value from 100 to 10 (you can play with other blend modes and values to see which ones fulfill your needs). You can see the results in the main edition window.

Now, your base texture will look similar to the one shown in picture Final texture with wrinkles.