How to Paint Diffuse Maps in Your Farming Simulator Mod
You can paint diffuse maps in your Farming Simulator mod. In the 3D View, change from Object mode to Texture Paint mode using the Mode drop-down menu in its header at the bottom of the window. You should see brush settings appear in the Tool Shelf along the left side of the 3D View and an overlay of your UV layout in the UV/Image Editor.
Also, while in the UV/Image Editor, you may want to hide its Properties region (N), show its Tool Shelf (T), and switch its interaction mode from View to Paint using the drop-down menu at the bottom of the window.
Your brush settings are synced between the 3D View and the UV/Image Editor, so you can quickly switch back and forth, painting in whichever editor is most appropriate. And as you do so, the other editor updates simultaneously so you can see the results of your painting.
Some artists choose to paint their entire model this way, which is especially nice if you have a graphics tablet with a pen. Using this type of tablet makes it feel a lot more like a painting and drawing experience. Combined with Blender’s masking and painting tools, you can add quite a bit of detail.
When you work on your texture in a 2D image editor, you may miss having the overlay of your UV layout. Knowing what part of your object you’re painting can be handy. Fortunately, Blender can help you get your overlay back.
If you toggle into Edit mode (Tab) and change the UV/Image Editor’s interaction mode from Paint back to View, you can choose UVs→Export UV Layout from the header menu (you may need to enable the Export UV Layout add-on from User Preferences to see this menu option). Now you can load your object’s UV layout as a separate layer in Photoshop and use it as a frame of reference.
As you update your texture in your 2D image editor, periodically save or export your work back to the PNG image. If you do, you can choose Image→Reload Image from the UV/Image Editor’s header menu (or press Alt+R) in Blender, and the texture will update in on your model so you can see the results of your hard work.
When you finish texture painting, make sure you disable the Shadeless checkbox on your object’s material so it reacts properly to light and shadows again. You should also press Numpad-slash (/) to get out of Local View.