Augmented Reality from A to Z using Blender, Unity and Vuforia | part 3 : Unwrapping


Video transcript :

Unwrapping

Assalamualaikum. My name is Widhi Muttaqien.

This is the third part of the video tutorial series. In case you stumble upon this video directly be sure to check the previous videos before moving on. The tutorial series is about developing augmented reality product from A – to – Z using Blender, unity and vuforia.  These tutorials are all based on my previous experience developing my own augmented reality product which is this flashcards Arabic letters and numbers augmented reality. Basically a flashcards to help children learning Arabic alphabet using augmented reality. I leave links below in the description if you like to learn more or purchase it from amazon.

Lets continue our lesson. In this video we’re going to unwrap the 3D model. Now because Carny -our carnivore plant- will be exactly symmetrical. We actually only need to texture the half side of it. Later we can use the mirror modifier to get the other half side. All of the 3d animals in my product use this technique. Here is one of the 3d animals model in our product which is a gorilla as you can see. Notice the texture is only for one side. And we use mirror modifier from modeling all the way to exporting it to Unity engine. Blender’s mirror modifier is very smart and powerful to accommodate bone weight.

Okay lets select Carny’s head first. Open modifier tab in the properties and uncheck the x mirror plane. Then hit apply button. This will flatten up the modifier and update the actual geometry. Now lets move on to the trunk. Go to edit mode and rotate the viewport so we can see the bottom part of the pot. We need a line from here to here. So select this vertex and this vertex, hit j. We now have an edge connecting the 2 vertices. Lets delete the right side of it by going to the front viewport by pressing 1. If your 3d view is still in in perspective press 5 to make it an orthographic view. You can see the word ortho up here, stand for orthographic. Now press Z to enter wireframe mode. Then press b to enter box selection and just click and drag like this to select the right side of carny. Which is left side from our point of view. After we have all of these vertices selected. Press x and choose vertices. Now we have some thing like this.

We can now start unwrapping our model. First select the head and go to edit mode, make sure we’re in vertex mode. Then select this one. Press and hold ctrl then right click this one. Then this one. So all of these edges at the lips are all selected. Now to tag this edges as unwrap seems. We need to go to tool shelf and choose  Shading -UV tab then click mark seam in here. This will make the edges become red indicating that they are currently set as uv seams. Next we want to create another seam from here to here. So, select this vertex. Hold ctrl and select this vertex. This will create a selection like this. Click mark seam again, to define these edges as uv seams.

For the tooth. Just go to edit mode, go to edge mode and select this edge. Mark it as seam. done

Okay now lets move on to the trunk and the pot. Lets start from the bottom of the pot. Press alt and right click on this edge to select this whole edge loop. Mark seam. And then this edge loop. Mark seam. And the last one is this edge loop between the dirt and the trunk. Mark them also as uv seam. Okay we’re finish defining uv seams. For the leaf we don’t need to add any uv seams as it is already flatten out.

Okay guys if you are confused about what is unwrapping? As I mention before in the introduction video that this tutorial is not for beginners. So you should already be familiar with  the basic concept of UV mapping and unwrapping before taking this tutorial. Okay.

The next step after defining the UV seams is the actual process of unwraping it and layout the uv islands so they fit into an image texture map without any overlapping faces. To make our life easier lets first join all of these objects into one. Before we do that make sure the main object which is this pot in our case has the default scale values of 1. If not. Select the pot object and press ctrl+A then select scale to apply the scale transformation. Okay to join all of these objects, first we need to make sure that we are in object mode. Then select all of them by pressing “A”. Then make sure the trunk-pot object is in yellow color. This yellow color indicates that the object is set as active object. Why this is important? Because when joining multiple objects the active object will be used as the main object where all objects will joining in. If this is not highlighted with yellow color but instead with orange color then we need to hold shift and right-click on it once. Okay now to join them we need to press Ctrl+J. After they are all joined in. Go to edit mode by pressing tab. Go to face mode and press A twice. To unwrap all of these faces press U and then choose unwrap up here. It looks like nothing has happened. But notice when we create another panel up here and change the panel type from 3d view to uv/image editor. We can see that unwrapping is actually has happened.

Blender has done a very good job making uv layout for us but in my opinion the UV islands are too close to each other. We can fix this by going to the tool shelf. Notice we have 0.001 margin value down here. Lets just increase this to 0.05. And hit enter. Now we have more margin or in other word more space or gaps between these uv islands. Smaller gaps actually means more space is being used from the texture which is a good thing because we’re not wasting memory that way. But it will be harder for us to draw on top of it in image editing software as we have more risk of color bleeding. Okay guys that’s it for unwrapping. See you in the next video where we will cover texturing process. -In sya Allah-

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#unity #blender #tutorial #augmentedreality #vuforia