Hello and welcome to GreyBeard’s Blender Tutorials this is my first video tutorial so do not expect miracles. it is on LSCM UV-mapping. A new features in blender 2.34 what is UV-Mapping? well UV-mapping is the art of wrapping a 2D picture around a 3D object. Each face of your 3D mesh is mapped to a corresponding area on your 2D picture image. This allows you to use paint program such as Photoshop and the Gimp, to make high quality images that can be placed exactly where you want on your 3D object. How is UV-mapping done? Well UV mapping is accomplished by cutting the 3D mesh strategic locations and unfolding it onto a 2D plane. Imagine peeling an orange and then laying than peel flat on a table. UV-mapping is always compromised. The more cuts you make to the mesh, the less distortion you have when unfolding the mesh. More cuts however, means that the 2D image can be more difficult to paint since you have will have to match more seams.
What is LSCM? LSCM stands for Least Squares Conformal Mapping surveyors of long use this Squares, corrections on there traverses in order to distribute the air equally amongst all the data points. This is the 3D version of that, what this mean to regular human beings such as one of the 3D modeling. After you defined where you want your 3D mesh cut using the LCM tool will unfold your mesh automatically while attempting to keep the distortion to a minimum. It does this by trying to conserve the angles in the geometry.
This is not always successful, you might you more often than not you will have to touch up the results so LSCM mapping. The new pin feature helps us to do this as you will see later. Lastly, I just like to give you some general strategy for UV-mapping. Try to put the cuts seams in your 3D mesh where they are hidden or where they are natural seams on your object. For instance you put seems under a hair line where colors for instance might be continues over that area or weather there is a natural change in color you will not have trouble painting by the seams then.
If there is a choice between distortion and a seam in an awkward place, it is usually better to go with a distortion. The effects of distortion can be mitigated by using a high resolution imagery UV map, say 2048 by 2048. There are two types of distortion and one is much more acceptable than the other, the unexcitable type is when you have small area on your 2D image, in other words huge pixels being mapped to a large area on your 3D object. You will see a lot of stretching and the results can be quit ugly
The more acceptable type of distortion, in fact it can sometimes be helpful as if you have a large area on your 2D image and it is being mapped to a small area on your 3D on your 3D object. That means you have a lots of pixels getting put into a small area which means you can actually add more detail. For game engine users and users of all older video cards, always use image sizes that are a power of two in square. This is a limitations of open GL and newer Video card do not seem to have this problem but just to be safe and it is not that difficult, I always stick with power of two square image maps.
Now that we got that out of the way, I am going to start on the Blender stream part of the tutorial. This is the object that we are going to UV map by pick it because it is rather hard to map this using LSCM and then we can use pinning to do the corrections. First thing I always do when I am UV mapping is make sure all my normals are pointing in the right direction so I am going to go down to. I am going to zoom in on the buttons here Control+Up Arrow, you can see I am going to make sure I do not have double sided on, Going to front view, tab into edit mode, select all my vertices CTRL+N and we got this recap normals outside dialogue, it aid to deselect all my vertices. Again CTRL+Up Arrow, I will go to full screen mode.
Now we have to decide were we want our mesh cut for mappings, what I am going to do is I am going to have a central area and the two globes on the end I am going to have a disk with four petals sticking out of it and will map the two. We will also have to cut the two, the long to one edge so that we can unroll it. B for box select and I am going to select some vertices then it is CTRL+E and this edge specials menus comes up within a mark or seam by deselect those vertices again you will notice that the seams are shown darker and a little thicker. I wish it was a different color but it was not, do the same for the other side, B for box, CTRL+E, mark that seam.
Now, I am going to mark some of the cuts, I can do two sides at once so all A button and then B for box 1, 2, 3, 4, 5, 6, 7, 8 deep, so I selected that, now box, 1, 2, 3, 4, 5, 6, 7, 8 top view, box, box, CTRL+E, mark seems. Now we have got are two globes map you will see there is a disk and there is a four petals will come of. We got our central area which we still have our cut on so I will go to bottom view which is the Shift+Numeric Keypad Number Seven, and I am going to go in here and select this vertices, CTRL+E and I have mark that seam. Front view again, I am going to go into UV face select mode and click all to deselect all the phases and we can see the cuts that we have made and how we can try to imagine how it is going to be unwrap, you can see the cut along the bottom we are to here as well.
So CTRL+Up Arrow to go to other full screen mode, I am going to split my screen and go to the UV image editor, back to this window, A to select all our vertices, zoom out a bit here. View LSCM and I will make this full screen now. You will notice that our two globes map really well but our central one did not. So now we have a couple of choices. We can try to play with this with pinning but it is pretty ugly and it is not going to make a nice mapping anyway. So, what we are going to do is we are going to add another scene onto our object. So, let us go back, back into the object mode, tab. Went to top view, so make it full screen, all box, I put a single on the top, CTRL+E, mark scene.
So now tab, tab all, divided our object into four areas. This globe, this side of the neck, the other side of our little neck in between the globes and the other globe, so we should have 4 islands of vertices when we do our mapping, back to UV phase select, up, Unknown Speaker:, LSCM. Make this full screen and we will zoom in. Now you will notice that this fan shape and this fan shape should be the same size. Now we can correct that with pinning which I will show you how to do later but first I want to show some new select options that are available in 2.34, one of them is the stick UV’s to a mesh vertex. Now if we use this for selection you will notice you will get two yellow arrows in the corner here and we select a vertex. You will notice that other vertex is that share the same vertex on your 3D object, are all highlighted at once and if you grab them they, you move them all at the same time.
The other select option is the local one which has a single dot which is the one I use the most. It is useful if you want to select, just click select and it moves all the connected dots together, notice if that was not on and I select a vertex and I grab it, you will notice how it is discontinuous. So I am going to set this to the local mode and I am going to make an error now. In order to try to correct this I am going to do some pinning but if I do not pin the other islands or at least put one pin vertex on the other islands, we are going to create a mess and I will show you how that happens and how to fix it. In the UV and in the LSCM unwrapping, what it do is it tries to maintain the same angles so what it does is it starts off at one end and keeps on maintaining the angles. As it goes trough and it starts shrinking and shrinking and shrinking. So, what we are trying to do is we are going to pick two vertices on opposite end and meet those fix and then let the LSCM work its way around those two vertices. This should give us some more symmetrical thing usually do this across like from a large side to the small side and this happens also sometimes when things are tilted. If you select opposite vertices, they will sometimes reline them selves.
So I am going to select that one and that one and P to pin and because I have not selected this you will notice we are going to get quit a mess here. When I press the E button and we can LSCM unwrap from here and you will notice all the silver lapping staff here. Now we could fix this by selecting a vertex and then the L key for link vertices and grab it with the GT and move it out of the way, link, grab it and move it out of the way but you see we still got quit a mess so you want to make sure you pin at least one vertex on every island that you have in your UV editor.
Now, to correct this, just select all the vertices press Alt Key which removes all the pins and then press E and then unwrap again and it will get back to our original. So, now I am going to select at least one vertex on every island, so I will select the middle one here, P pin, I will select one here, P to pin and I will select this two here, P to pin remember we are going from that word got an arrow toward that Y in order to try to make it symmetrical. I will do the same here, P to pin. Now, we can press the E key again and unwrap. Now, it is much better but it is still not perfect, we zoom in here you will notice that there is some overlap here, so what we are going to do is take the lower ones and move it up and the upper once and move them down.
So we are going to select that one and that one, pin them, grab them with the G key and move them up, say two and a half. Do the same thing with the lower once, P to pin them, G to grab them, down to and a half and then we are going to do an E and we unwrap and you will notice that is a much better shape. We should try that over here with this one, P to pin, G to grab, go down two and half, P to pin, G to grab, up two and a half and we can do our E unwrap. Now we got a pretty decent, unwrapping all that remains is to arrange it nicer so we can scale it up for, select one vertex, hit the L Key to get all the link once, G to grab it, R to rotate it, S to scale it. Try a bit too big, L for link, R to rotate, L, S to scale, L, grab, scale by holding down the control key, I can scale it, say to 1.3.
So, I can scale this one to same amount, select the vertex, L, G to grab, S to scale hold down the control key so I can get 1.3 exactly. Okay, so now we have a nice mapping. Now, let us load an image in here, image, open. Turn out the hidden files, load in the test map. Let us go to full screen mode, I went to potato mode, and you can see your mapping there.
Now to make that mapping also visible in object mode, we will go down our menu here again. Well, first we will go to material menu and you will notice under materials there is this text face button, we wan that pressed. And then when we go to object mode and tab in and out. We will have our mapping displayed in that menu. I am going to make this full screen so we can have a better look at mapping. You will see there is a very little distortion although we do have quite a few scenes to deal with.
Okay, now we are going to export our mapping, if we go to scripts window, under the scripts menu under UV there is UV phase layout, we will go to here you can set your size. Remember my power of two we will go to 512. I can get it to go there. It will use the name of my object because that is the press so it will be sphere. TGA, saving that as an TGA file and now I am going to export it. Take sometime to work trough it, it is all done and now I will show you some picture of what it looks like. Here is what is exported that you take to your paint to paint. I hope you enjoyed this tutorial I know I learn a lot in making it, happy blundering.
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