At this point, everything is ready for the unwrapping.
Put the mouse pointer on the bottom or on the top horizontal borders of the 3D window. As the mouse pointer changes to a double-arrow icon, right-click and in the Area Options pop-up menu select the Split Area item; then, left-click to obtain two windows and switch the left one to UV/Image Editor.
The two windows
To unwrap the mesh in Blender, several options are available; however, the one we are going to use now is the basic unwrap, the result of which we will edit and refine later:
- Ensure that the UV/Image Editor window is not set to Render Result, otherwise it won't display the UV islands.
- Select the Gidiosaurus_lowres object and enter Edit Mode. Select all the vertices (A key) and press the U key; in the UV Mapping pop-up menu, select the first item, Unwrap:
Unwrapping the mesh
After a while, the UV layer of the unwrapped mesh appears in the UV/Image Editor window; as you can see, several things can be improved. Moreover, we are still using only half of a mesh.
- Go out of the Edit Mode and go to the Object Modifiers window; apply the Mirror modifier.
- Go back into Edit Mode and press 1 on the numpad to go to the Front view; press Ctrl + R and place a median seam through the head part of the mesh, as well as through the pelvis part:
A new loop cut
- Press Ctrl + Tab to switch to vertex selection and press Z to go into the Wireframe viewport shading mode, and then box-select the vertices on the left-hand side of the mesh (which is the side created by the Mirror modifier).
- Go to the UV/Image Editor window; if not already selected, press A to select all the UV islands of the UV layer, and then press Ctrl + M | X | Enter to mirror these selected islands.
- Press G to move them (temporarily) outside the default U0/V0 tile space, as shown in the following screenshot:
The selected half body vertices and the corresponding UV islands outside the U0/V0 tile space
- Go to the 3D view and press A twice to select all the vertices; go to the UV/Image Editor window and press Ctrl + A to average the size of all the islands reciprocally.
- Select all the islands and press Ctrl + P to automatically pack all of them inside the UV tile.
- If you are not satisfied with the result of the Pack islands tool, adjust the position (G key), rotation (R key), and scale (S key) of the islands; group together the similar ones (for example, the teeth, talons, arms, and so on), but try to place them to fill the image tile space as much as possible. To select one island, just put the mouse over it and press L, and Shift + L to multiselect. Use the X and Y keys to constrain the movements of the islands on the corresponding axis:
Adjusting the UV islands' position
- When you are done, ensure that all the vertices of all the islands in the UV/Image Editor window are selected, and click on the New button on the toolbar of the UV/Image Editor window; in the New Image pop-up panel, set Width and Height to 3072 pixels, and Generated Type should be set to UV Grid. Then, click on the OK button to confirm.
- Go to the 3D window and press Z to go in the Solid viewport shading mode. Then, go to the Properties 3D view sidepanel and under the Shading subpanel, check the Textured Solid item.
- Go out of the Edit Mode and save the file:
Assigning a grid image to the unwrapped UV islands
This should be enough; even if the halves of the mesh are disconnected, Blender can perfectly solve the mesh painting without visible seams.
However, if we look at the character shown in the Textured Solid mode in the 3D view, it's clear that the unwrap of some part of the mesh could be better; for example, you can see a difference in the size of the mapped grid in the head/neck area, inside the mouth, and on the arms and legs (look at the arrows in the following images):
Differences in the mapped grid image
Although this is not a very big issue, the unwrap can be refined further to avoid distortions as much as possible, as well as potential future problems when we'll paint the character textures; we are going to see this in the next recipe.