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Over the course of this extensive 7 day series. Shray Khanna will guide you through the entire process of creating a next-gen, low poly vehicle using Maya and Photoshop. Throughout the series, Shray covers the complete next-gen pipeline in detail. In day 3 we'll be covering the UVMapping process.
Also available in this series:
- "Next-Gen Armored Car" Day 1
- "Next-Gen Armored Car" Day 2
- "Next-Gen Armored Car" Day 3
- "Next-Gen Armored Car" Day 4
- "Next-Gen Armored Car" Day 5
- "Next-Gen Armored Car" Day 6
- "Next-Gen Armored Car" Day 7
For UV mapping the first thing we'll need is our UV Texture Editor, so for that go to Window>UV Texture Editor.
You will now have a new window open up for UV editing. In the window you can see the UV's of the currently selected mesh.
Now there are several methods available to unwrap any kind of mesh, i.e. "Planar" mapping for plane surfaces, "Cylindrical" mapping for cylindrical surfaces and so on. And then there is "Automatic" mapping which I like the best, as it maps complicated surfaces into several parts depending on the surface. So with the top hatch of the car selected, go to Create UV's>Automatic Mapping.
Now you'll see that some kind of projection has appeared surrounding the mesh (this is how it maps it.) You'll also see various parts of the mesh mapped accordingly in UV editor window.
Now a small introduction to the UV's They work just like regular Vertices, Edges and Faces but are only editable inside the UV editor. You can select them in the 3D viewport, but can only edit them inside the editor. To start, select the UV's of the corner part and then in the UV Editor go to Polygons>Unfold (as shown below.)
Automatic mapping doesn't always open the UV's into the correct shape, so Unfold will do this for us. Now move the selected part to the side, and in Edge mode (right click, hold and select Edge) select these side edges and go to Polygons>Move and Sew UV Edges.
The Move And Sew option does just what it says, it moves the Uv's of lighter weight (lesser UV's) and sew's them to the corresponding parts of the mesh.
Now try selecting different parts of the UV's to get to know which part is which, and how they correspond to each other. This will make it much easier to plan your mapping. For instance, the center edge selected in the image below is for the rear of the hatch. So select that edge and go to Polygons>Cut UV Edges. This will split the connected UV's
Now as you select the corner edges of the main surface, you'll notice that a few edges of the rear surface automatically get selected, it actually shows you the corresponding surface that can be connected.
With the same selection, Move and Sew the UV's so they connect together. And then select the lower UV's and make them Unfold UV's
Use the same Move and Sew UV's procedure on the lower front section as well.
Now in the above icon tray select the icon highlighted below, it's a toggle for displaying Open edges/Seams in the UV's Now select the center open edges of the mesh and sew them.
Now we need to split the lower section of the hatch from the upper part, and then re-join it. As this will help us when texturing.
Now select the front edge of the lower part (1) and Move and Sew it. Repeat the process again and you will get the completed section of one part.
Now using the Move and Rotate tools, align the piece towards the axis to make it straight (1). Then Unfold and Split it in the center, creating two halves. Now place them on each side as shown below (2).
Now Move and Sew the two edges of the front part together.
Next select the Edge loop of the inner section. To do this, select one edge, right click and hold and select the Edge Loop Option.
Move and Sew them, you'll notice a few of the corners get messed up (1). No worries, just select them along with the whole section and Unfold them (2).
Now Select the edge loop around the center part (1), Move and Sew them (2).
There is also a very useful tool for selections, which is called "Select Shell". Select a few UV's and go to Select>Select Shell. It will select the complete part and then Unfold it.
Now by following the same procedure, select the outer loop. Move and Sew and then Unfold it.
Now select the center edge of the part and Cut it (1), then select these edges and Move and Sew them (2).
Select the outer edges of the selected part and Move and Sew them (1) and at last Unfold them (2).
Now select the Turret and map it using Automatic Mapping.
Now we just need to Move and Sew the UV's to connect it (as it's a simple cylindrical surface.) But for this piece we need to take care of the seam. Always try to place the seam in an area that is going to be the least visible in-game, so for this part I chose to have it run along the bottom edge. Select that edge loop and Cut it.
Now it's as simple as anything, just Select all the edges except the seam (1) and Move and Sew again, do the same for the lower edges and then Unfold them (2).
Now Select the inner center faces of the turret and go to Create UV's>Planar Mapping (1), as automatic mapping wont give it this shape in UV's (2).
Now just place the UV's in a corner so that you will have a clear layout while paging out the UV's
Now for those of you like myself who don't want windows floating around while working, we do have another option. Which is to set our UV Editor window as a viewport instead. To do this go to Panels>Saved Layouts>Persp/UV Texture Editor.
Now select the base of the turret and do the same, apply Automatic Mapping first.
Now we just have to follow the same procedure as before for each and every mesh. Just recognize the shapes first and plan the mapping. Then select the edges to Move and Sew the UV's
Now Move and Sew these edges (1), and then Select the side edges and Move and Sew them too (2).
Select the edges shown in the first image, and Move and Sew them (1). Then select the side and top ones and do the same (2).
Now select the edges of the small part, and Cut them. Then Move and Sew these edges on the front part. Finally Move and Sew these two edges as well.
Unfold them one by one, and place them in an organized manner (as shown below.)
Now select the faces of the spherical part, and go to the Create UV's>Planar Mapping "Option Box" (1). Then in the option box, set the "Fit Projection to: Best Plane" (2). This option will make the Planar mapping use the angle required to automatically map the surface.
Now select all the UV's of the mapped surface and go to the Polygons>Unfold "Option Box" (1). In the option Box, tick the "Pin UV border" option (2). This will pin the UV's border and only Unfold the inside of the UV's, and keep the surface from bending or anything.
Move the UV's close to the Turret base's UV's and place them properly (as shown.)
Now Select the Small part near the turret, and Automaticly map it.
Again following the completely same procedures, use Move, Sew and Unfold to achieve the output shown.
Now the same breakdown is shown below for the lid. Duplicated it for the other one.
The breakdown of the Front Headlight is shown below. I mainly used Move, Sew, Unfold and Cut.
Just the same way as before for these small parts.
Now select one of the side faces of the lid pipe, and apply Automatic mapping to it (1), then select the right side faces and do the same (2).
Now move the UV's of the right side, and then the 3rd part. Do the same with the last remaining part of the pipe.
Now select the 4 Edge loops and leave the below edge only, then Move and Sew. Then Unfold it. Finally select the horizontal edge loops one by one and Move and Sew them to make it all a single part.
Now select the unwrapped pipe and then the other one. Go to the Mesh>Transfer Attributes option box". Then tick the option of "UV Sets to All", and "Sample space to Component", and select the options as shown below. You will now get your UV's transferred from the first Pipe to the second one. You can use this option to Transfer UV's successfully to any replicated meshes. The only condition is, they must have the same Poly/Vertex Count.
Now just unwrap the hook of the lid pipe using same procedure (basic shapes only), and then transfer the UV's to the other one, same goes with the the cylinder below.
Map the two antennas on the top using the same procedure (Basic shapes only).
Do the same procedure for the nozzle of the rear gun (Basic cylindrical shapes only).
Now here is the breakdown of the part behind the nozzle using the same procedure of Automatic mapping. Then Move and Sew the UV's, then Cut the UV's, then Unfold the UV's, and the Final UV placement (10).
Now Select the Handle bar of the mounted Gun and Follow the breakdown procedure.
Unwrapped the lower part (1), and then the connector following the same procedures (2).
Now the cylinder in-between, and overlap the symmetrical parts of both sides to save texture space.
Now for the last part of the mounted gun, below is the breakdown of the mapping, and for this particular part. I deleted one half and unwrapped only the left half .After mapping one half, I Mirrored it, this way we save both time and texture space.
Now we move to the Front wheel arch, I decided to optimize this object further, so let's do it now. Select the alternating edges of the lower section and collapse them. Then before moving onto unwrapping, select the left half of the wheel arch and delete it. We'll mirror it after unwrapping one half.
Now below is the breakdown of the automatic mapping of the half wheel-arch. (I did a little bit of optimization on the mesh here as well).
Now mirror the half Wheel-arch and then select the UV's of the second half. Flip them vertically, then move them around to arrange them in a proper manner. Now here I didn't mirror the UV's, as this is part of the front of the vehicle and mirrored textures will be quite visible. We also want to have specific variations in terms of texturing so that it will look more authentic.
Now for the main base, select the front, top and rear part faces and Planar map, and unfold them (1). Then map the sides and bottom surface the same way. Then Move and Sew the joining side edges to the top (2).
Map the front pipe the same way as we did the hatch's pipe lid (Same procedure as before).
Now using the Automatic mapping procedure, unwrap this front hook as shown and then transfer the UV's to it's replicated part.
Now for the few proper cylindrical parts we can also use Cylindrical mapping only. For the front mounted gun, select these faces and Go to Create UV's>Cylindrical Mapping (1). And you'll notice a cylindrical Projection appeared around the selected faces, but as we can see it's not aligned properly (2).
Now in that projection, click on the circle floating around the Pivot point, and you will have the rotational axis visible (1). Rotate the cylindrical projection and align it with the shape (2). Now you'll see that the mapping opens up according to the shape, finally select the UV's and Unfold them (3).
Now map the front cylindrical shape the same way we did in the last step, and place it like this (1).Then just open the front faces using Planar Mapping, and place them properly (2).
Also map the Gun nozzle using Planar and Cylindrical Mapping as shown.
Here is a Breakdown of the small parts of Front headlight, Unwrapped using mainly the Automatic mapping procedure.
Here is the Front Lid mapping breakdown, using the same procedure once again (Follow the four images below).
Now duplicate the lower parts of the lid and replace them with the other one, then use Automatic mapping for the upper part of the second lid.
Now Duplicate the round lid from the upper part and place it on the lower lid (as the two shapes are mostly the same). Then delete the top faces which are not required.
Then Unwrap the holder using Automatic mapping, and move the UV's of the lower lid. Replace it with the new ones.
Now here are few more mappings of the smaller parts using the same procedures.(1. Pipe procedure) (4. Same clip holder as we have above on the pipe lid over the hatch )
Now on the side cylinder use Cylindrical mapping as this will map it precisely on the cylindrical surface, then for the side faces use Planar or Automatic Mapping. And overlap the adjacent parts, as shown selected in (4) and (5).
Now the mapping of the pipe joining the Cylinder with the base.
Here is the mapping of the small utility box just above the rear wheel-arch. Use Automatic Mapping and Move, Sew and Unfold the UV's
Now a few more small parts mapped using the same procedures as before.
The rest of the small parts over the back are mapped using the same techniques.
Now Transfer the UV's from the above belt we just unwrapped, to the lower one holding the shovel as they're the same. (only the vertices are edited in terms of placement). Duplicate the belt and place it over the center belt and delete only the side holders.
Now the Breakdown of the mapping of the Shovel is shown below. Use Automatic Mapping and Move, Sew, Cut UV's and Unfold UV's
And here's the mapping of the small box placed over the back.
Here is the mapping of Tail light and small holder at the back using Planar mapping and Automatic mapping respectively.
Here is the Breakdown of the mapped parts of the Exhaust pipe. Unwrapped using only the Automatic mapping procedure. Remember to Transfer the UV's to the other exhaust pipe as well.
Here is the mapping of the utility box on the rear part, as shown below.
Now the Rear wheel-arch, just like the front wheel arch, it's done with Automatic mapping.
Now for the Wheel, start with Automatic Mapping first (1), then select the 2 edge loops of the tread (2), and Cut the UV's
Now select this edge ring and Cut these UV's Select the edge loop just below the tread and Move and Sew it. Then select the edge ring again, and Move and Sew them. Now select all the UV's and using the Pin UV Border Option, Unfold them.
Now select the remaining edges of the rear part and Move and Sew them, then select the edge ring and Move and Sew it. Then Unfold it. Then select the Edge ring of the tread part.
Move and Sew that edge ring, then Unfold it (1). Then move the center portion of the rear rim and place it in-between the outer rear rim (2).Then Move the center part of the front side rim and move it in-between the outer front rim (3). Then select the edge ring of the rear rim's cylindrical faces.
Move and Sew the edge ring, then select the UV's of right side and using scale, scale them on the X axis to straighten them. Then select the rest of the UV's and Unfold them.
Now select the edge ring of the 2nd set of cylindrical faces of rear rim. Move and Sew them, then place all these cylindrical parts along the side of the tread. Now select the Rear faces of the tire, and place them over the front tire, as this will save us a lot of texture space..
Now select the center edge loop of the rim and Cut the UV's (1). Then Move this particular part and place it around the center rim part. Then place all the parts in the center (3)(4).
Now we need to match the aspect ratio of our UV's. This will make sure we have an even resolution on all the parts of the model. For this, first go to Hypershade, then select the "Favorites" tab, and from the second tab select "File". You'll notice a file node is created in the Work Area tab.
Now click and hold on "Lambert1", and with the middle mouse button, drag it to the Work Area tab.
Now Double left click on the File node, and select an image file (can be a jpg or tga) of a checker pattern (it can be either b/w or colored checkers). You can search for "Standard numbered checker textures" in Google, or you could make one of your own. It's just used to match the pixel aspect ratio of the whole model.
Now after calling in the image file in File node, click and hold the middle mouse button on the file node, and drag it to Lambert1, you will see this dialog box open in which you have to select the "color" parameter.
Now you can see a node connecting the File and Lambert1. And also the numbered checker has appeared on the Vehicle (as lambert1 is already applied to it).
Now double click on the Placed2dTexture2 node that's connected to your applied file. In the Attribute Editor, Make the "Repeat UV" 10.00 in both fields, this will give the texture a tiling and make the checkers more visible on the vehicle.
Now if you look closely, you'll find differences in the checker size on various parts of the model. This is known as "pixel aspect ratio", and it's a very important part of the whole process and is something that can never be ignored. Now these checkers stand for the textures which are going to be using later, so we have to match the sizes of the checkers on each part that will have the same textures.
Now for this purpose, select the shells of the UV's of each separate part, one by one. And scale them in the UV Texture Editor to match the checker size.
In the same way scale the Rear wheel arch's UV's to match the checker size
Now scale the UV's of the hatch, and match the size of the checkers on the base.
Now scale the UV's of the Turret and the other small parts, to match the checkers size.
Scale the UV's of the front pipe and match the checkers size.
Match the Checkers size of the Wheel using the same scaling technique.
Using the same scaling of the UV's, try to match the checker's size on all the parts of the model, like shown below.
Now start placing the UV's in the "0-1" UV space, as this will be the area where we will have our texture. This placement is called Page mapping of UV's
Just like this, start selecting the big parts first and place them in the UV space.
Now start selecting the smaller parts and place them in the UV space that's left.
Complete the placement of the UV's, by selecting each part ,one by one and placing them to utilize the maximum space available in the UV page (0-1 space). Now remember there are no hard and fast rules to follow when setting up a page map, just keep in mind that aspect ratio and page mapping are like a Puzzle, or like Tetris, you need to fit all the pieces together.
And here is our much awaited Armored Car Low Poly Model with UV's.