Now that you had some time to mock or model something up, it needs a texture, and it also needs to be prepared for exporting. Because we’re obviously doing this go get the model to Minecraft, right?
So, today, we’ll take a look at how to UV-unwrap, optimize and fix errors that might have occurred during the modeling process.
But before we get into that let me share another useful Cinema 4D tool, that’s going to help you out when texturing and modeling. It’s called Symmetry. And what it does is mirror any object along the selected axis.
Much like with the cloner object we had a look at in the previous post, you just put objects you want to be mirrored as a child of the Symmetry and you should see an instant update. You can find the Symmetry object here:
If you’ve done any model that isn’t just a simple box or block, your scene should look something like the picture bellow here. That’s completely normal, but it’s not something we can just export or texture. We first need to UV unwrap the model, so that the texture can be applied. Now if we go by the Wikipedia page on UV mapping this is what it sais:
UV mapping is the 3D modeling process of projecting a 2D image to a 3D model’s surface for texture mapping. But if we simplify it even further it’s stretching an image over the 3d model. Or if you picture cutting open a box into a flat piece of cardboard.
And for this we’re going to use the Cinema’s built in tool, called the BP UV edit. (BP stands for BodyPaint) You can select it from the drop-down menu in the top right corner. Now don’t get scared about the change of layout, as everything is still there, and if you ever want to get back, simply select the "Startup" layout from the same menu, and presto, you are back to where we started.
Now I guess I should briefly explain what is it that you are seeing. The screen is divided into 5 sections. On top, you have the model on the left and the texture area on the right. (That’s where the most of our work will be done) Now in the bottom row, you have 3 fields. Far left are your objects or cubes you have created, the middle is where the info on the selected tool or object is, and on the right is where the actual tools for the UV mapping process are. Here’s also an image of the screen:
The 5 different views again are as follows:
- Perspective view, where your model is presented.
- Texture area. Here you will open and see the 2D texture you are using for the model.
- The UV mapping commands. We’ll be using these to actually unwrap the objects.
- Is where you can see the texture or object properties.
- Here you have the list of all your objects in the scene.
So, what’s the general idea? Well we’re going to make all the cubes editable, and then we’re going to unwrap them, and finally position them on a texture, that we’ll use as a guide to have pixels be the right size, you can find the reference pixel images below. (Or you can just create it by making a grid with 2 different colors)
First things first. On the screen 2(I’m just going to refer to screens, you have the numbers above), select
File ->New Texture and you’ll set the proper size. We’ve talked about sizes before, but go as small as possible (128x128px is a good start). If you have prepared a texture reference picture, or if you downloaded mine, you can just open it in the same menu. If the texture ever disappears on screen 2, you can get back by going to
Second, we’re going to unwrap the boxes(cubes). Now if you want to save some time and effort, you can skip the elements that are copied multiple times, or if they are mirrored since the chances are they will the textured the same anyway. But ok, we’ll get there. Select an object in the screen 5 and press
c. What this does is make the object editable, which means you can then modify the UV map. The object icon will also change into a little triangle. Now select the following icon on the screen 1:
Now having the object selected press
Ctrl+A, to select all the sides. Now comes the real deal. On screen 3 you’ll click the "Box" button. (This properly unwraps the cube and you can use it for all of them) If you’ve done everything correctly this is what you should see:
Now if you work on screen 2 you can select the UV map and move, scale and rotate it. Now obviously don’t rotate it by anything not an increment of 90 degrees or the pixels won’t match. But what size should I make the UV maps you ask? Well in the previous tutorial I explain the size of pixels in relation to box size. So a box the size of 1 pixel in game should, in turn, be 6,25cm. So if you divide the size of your cube by 6,25 you should get the number of pixels it should be on the texture. That’s why you have the reference texture loaded. Now you just do this for all the boxes and presto. You’re texturing. If you want to see how it looks textured, just assign the texture you’re using to a material, and assign the material to all the boxes you’ve UV mapped.
Now I know this is somewhat technical, but no one ever said it was easy. I came up with this method and it seems to work, but if anyone knows a faster way, I’m all ears. 🙂
This is it for today, but next week we’ll take a look at rendering, and maybe also exporting. If you get stuck or have questions, you can post it in the comments, or you can tweet me @Mrbrutall