abcabcabc » So you want to be a games developer! UV Mapping: The Basics

So you want to be a games developer! UV Mapping: The Basics

Posted on 2/28/2014 by with 0 comments

UVmappingBasics

If you have been following along with the fire hydrant project so far you should know by now that we have a completed model of a fire hydrant.

11

Today were going to show you the basics of UVing, this is to a lot of people one of the most hated jobs and confusing for beginners in modeling, but a necessary task to make your models look the best.

This is where most sites and courses would give you a history lesson about UV’s, but screw that. All you really only need to know is that when you model you work with three axes X, Y, and Z. So the next axes or coordinates are U and V and this is where you will be working on today.

So UV’s are nothing more than a flattened model on the U and Z coordinates to allow you to add textures along with a lot of other things to make you model look better. Let’s get started I babbled too much already.

BoxBox 2

OK so let’s look at these pictures of a cardboard box. Making a box like this quite east you can use a primitive that is provided for you in any 3D modeling application, but if we wanted to recreate this box in 3D for a video game we must make the UV’s so that the texture will line up properly.

A model is only as good its UV’s, bad UV’s = bad model most of the time.

Box Silo

For this all we really need to do is scale the box to the approximate size and add seams to where we break the model down. For this we will use the seams that are actually on the cardboard box.

A lot of boxes have extra flaps to make the box stronger, we don’t need to worry about these unless you are making them visible, like having one side of your box open.

ViewportlayoutShowUVSeam

Before we begin here we need to make sure that you are using the proper view and that UV seams are visible.

Viewport

OK here’s the view that you will need, you have the normal perspective view along with a UV 3D and UV 2D.

So what we need to do is look at our box and see where the seams should be.

boxSeam

Before you create any seam you must prepare your model, by first select the object manipulator tool and the select your model, and in this case our box model. Once selected then all you need to do is to go up to your UV/Materials tab at the top menu bar and then select recreate UV’s using XYZ coordinates.

Once you have done this in the 3d UV view should show your model correctly. Now you can create seams to unfold our UV’s.

BoxXYZcords

Now we need to cut our box just like it is cut on the cardboard version. So let’s select out edge manipulator tool, and select an edge that one of the seams should go. Then go up to the UV/Materials tab and select mark seam from the drop down menu. The seam should now be marked in blue indicating a proper seam.

BoxOneSeam

Now mark all the seams just as they are on the box, you can select multiple edges and do them all at once or just select one at a time till you get the hang of it.

BoxAllSeams

Now that all the seams are selected, let’s take a look at our box unfolded. This is what your model should look like when it’s unfolded if you marked the same seams.

Unwrapped small

 

Now let’s do this for the model. First use the object selection tool on the box model, then go up the UV/Materials tab and select Recreate UV with LSCM (Least Squared Conformal Mapping). Now if you did everything correctly you should get something like this in the UV2d window. This is your model unwrapped properly, just like the real life box.

ModelUnwrapped

The next thing you need to do is to make sure that your unwrapped UV are in the box, because output confines to what is inside the box only. Well, that’s mostly true, but that all you need to know right to basic understanding.

You can move the UV’s where ever you want, but just make sure there in the box before exporting.

UVLarge

Now clean up the UV’s by moving them as you see fit. You can move all the component just as you did as a model, I’m not going to much work with these, but you can if you want.

I am going to leave it here for this week and I’ll keep working on this next week. Remember to save your work and save often when creating models you never know when something might happen and then you lose it all. Next week I’ll take these UV’s and show you how add some textures to them and then I’ll return back to the fire hydrant project to get the UV’s started there.

 

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