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UV Mapping Mastery: Optimizing and Unfolding Turtle Models for Stunning Textures


🔴In this tutorial, we focus on optimizing the UVs for a turtle model from Zoodles.


🔴We demonstrate how to clean up unnecessary faces and improve texel density for better texture quality.


🔴Step-by-step instructions are provided for cutting, unfolding, and laying out the UV shells.


🔴We also explore transferring attributes and organizing the UVs for different parts of the model.




- Workflow

  • In our project, we’ll add the Turtle model from the ZooTools assets.

  • We can see that the model doesn’t have any UVs cut inside the UV editor.

  • The first thing we want to do is delete any extra faces that will never be seen on the model inside of a game or a movie.

  • These are the faces that are completely covered by other parts of the model.

  • We do this so we can save up memory and space on the UV Map.

  • For example, the left part of the model has all of the faces while the one on the right has faces deleted that won't be seen.

  • We can see that the texture density is greater on the left side.

  • We’ll start off by deleting the faces on the shell that are covered by the body of the turtle.

  • Select the shell and isolate it so that we can easily delete the faces we don’t need.

  • In this case, this one face loop is enough to delete.

  • We’ll repeat the same process on each part of the model, select the part and isolate it to delete the extra faces.

  • For the scales, we want to delete the faces that are completely covered up by the Turtle shell.

  • To make it easier to delete these faces, we can first delete a face loop then what is left of the faces in the middle we can just double-click and delete.

  • Make sure you haven’t missed any faces.

  • There are more scales on the belly of the turtle, repeat the same process we did previously.

  • Above the belly scales is the rest of the turtle shell. Isolate it and remove the extra faces.

  • For the nails, we only want to delete the first face loop. If we delete more than one we will have noticeable holes in our mesh.

  • The last thing we want to delete extra faces on is the eyes.

  • Now that we deleted all the unneeded faces we can select all of the UV Shells and Sew them so we can create our own.

  • Cut the head in half so we can have two equal pieces. We also want to cut the edge loop around the mouth because that’s where we have the most stretching in the mesh.

  • Select the head UV Shells, unfold them, orient shells, and lay them out.

  • There is still too much stretching inside of the mouth so we can directly cut the edge from the UV Shells.

  • Once we do that we’ll unfold and lay them out again.

  • For the legs, we’ll split them up so we can attempt to transfer the attributes from one leg onto the other to save us the time of opening up the same UV Shells for similar or equal parts.

  • We’re going to split the front and back legs as well as the nails of the turtle.

  • Select one of the front legs and cut the UV Shell into three parts.

  • One cut in the side of the leg and another edge loop cut where the leg starts to make way for the nails.

  • After the cuts, unfold, orient shells, and layout.

  • Inside Mesh open up the Transfer Attribute window, switch the sample space to Topology, select the leg behind the one with the nicely cut UV Shells then click on the Transfer button.

  • We can see that the UVs transferred nicely and there aren’t any stretchings.

  • If we try to do the same thing to the other front leg it will not work, we can see this from the checkerboard and how the squares are stretched and twisted.

  • Because of this, we need to cut the UV Shell on our own for this leg.

  • Cut it in the same way we did with our first leg, a cut in the side of the leg and another cut on an edge loop where the toes are.

  • After the cuts, unfold, orient shells, and layout.

  • Before we transfer the attributes we can first fix up the layout of the UV Shells to get the best amount of texel density like in the image.

  • After we fix up the layout of the UV Shells, select all of them, orient the shells, and layout again.

  • Now we can transfer the attribute to the other back leg.

  • For the nails we’ll cut one in half then after laying them out we’re going to use the transfer attributes to the rest of the nails on the turtle.

  • For the bottom scales we can just unfold them since their form isn’t complicated and doesn’t have too many faces.

  • After unfolding, orient shells and lay them out.

  • We only need one horizontal cut on the tail. Unfold, orient shells, and layout.

  • For the shell, we’ll cut one horizontal line and one vertical line that goes around the entire shell.

  • After the cut, unfold, orient shells and layout.

  • The scales on top of the shell can also be unfolded without making any cuts.

  • After you unfold, orient shells and layout.

  • The turtle does have a body that we can barely see but is still visible on many sides.

  • If we isolate the body we can see it’s just a stretched sphere.

  • The body can be cut in half horizontally.

  • Unfold, orient shells, and layout.

  • For the eyes, we can just unfold them, orient shells, and layout on both the iris and eyeball.

  • After that transfer the attributes to the other iris and eyeball.

  • This is how your UV Shells should look like when the entire body is selected.

  • Moving forward we’ll group up each leg with their nails (Ctrl + G) and select them through the workspace, not the outliner.

  • In the UV Editor select the UV Shells, orient shells and lay them out.

  • If you are able to, select the back leg without the nails, then with shift select the leg in front of it and transfer the attributes.

  • If the software is causing issues and the transfer isn’t working we’ll lay out the other leg manually.

  • Repeat this process for the other limbs, group up the leg and the nails, select the meshes, orient shells, and layout inside the UV Editor.

  • The same thing applies to the tail and body, select them, group them up, select UV Shells, orient shells, and layout.

  • Group up the shells and the scale, select UV Shells, and lay them out.

  • The head is fine being on its own and we don’t need to change anything about it.

  • And the last parts we need to group up are the eyes.

  • We can now see we have a lot of groups in our outliner and it is hard to tell which group belongs to what.

  • We need to fix this issue by selecting each group from the outliner, seeing what meshes are selected, and naming the group accordingly.

  • Before when we made UVs we assigned different materials to each group, in this case, we want our entire mesh to only have one material but each group to be placed on a different UV tile so the UVs don’t overlap on each other when we bake the model inside of Substance Painter.

  • To do this we’ll start by adding a Lambert material to the turtle and naming it.

  • When we select the Head group we can see that the UV Shell is on the U1V1 1001 tile, above that there is another UV tile with a different name.

  • On each different UV Tile, we will place a group from our turtle.

  • We’re going to leave the head on this UV tile and move on to the other groups and place them on their own UV Tile.

  • Select any group, in this case, we’re going to select one of the legs, holding down D + X we’ll move the pivot to the corner of the UV Tile.

  • From here we can hold down X and move the UVs on the Tile above.

  • We’re going to repeat this same process on the other groups till we have something like this in our UV Editor.

  • One problem we must avoid is, if we select a group and see that the UVs are overlapping on another UV Tile we must scale them down slightly so only one checkerboard map appears in one UV Tile.

  • Check the other groups and you’re done.


Bonus - UV Shortcuts

  • This bonus class focuses on using shortcuts to create UVs more efficiently without having to click the tools inside of the UV ToolKit.

  • We first need to have our object selected that we want to cut the UVs off, you also need to be ether in Edge Mode or UV Shell mode.

  • You can switch to these modes either in the Object Preview or inside the UV Editor.

  • When in Edge mode you can use the cut and sew options while in the UV Shell mode, you can Unfold, Orient Shell, and Layout the UVs.

  • For example, we will select the eye of the turtle and isolate it.

  • In Edge mode select all the edges, move your mouse to the UV Editor, and hold Shift + RMB.

  • We can see that a new menu will appear in the UV Editor.

  • Each menu is different between Edge mode and UV Shell mode.

  • For now, we want to Sew all the selected edges.

  • While holding Shift + RMB select the Sew option. Now all of our edges are sown.

  • An even faster way of doing this is by holding Shift + RMB and swiping in a diagonal motion toward where the Sew option is in the right lower corner.

  • This also applies to the Cut option, holding Shift + RMB and swiping towards the lower left corner.

  • When you have all your cuts on your model you can use the same shortcut while in UV Shell mode to Unfold and Layout your shells.

  • There are submenus inside the UV Shell mode that has the rest of the tools inside of the UV ToolKit.

  • If we want to unfold our shells we can either hold Shift + RMB and swipe quickly towards the left or hover over the Unfold menu which will open up another smaller menu for the extra unfold options then select Unfold.

  • Sometimes when we Layout our UV shells they tend to branch out to other UV Tiles instead of staying inside theirs.

  • They can also overlap each other which will cause further issues down the line when we want to texture the model.

  • To avoid this we can access the Layout options menu.

  • To open this Menu hold Shift and click on the Layout button.

  • In the Menu, we need to change the Shell Padding and Tile Padding from 0 to 5.

  • Once we do this we click Apply and Layout UVs.

  • Now if we cut and unfold UV Shells we can notice they are keeping their distance not only from each other but also from the UV Tile border.



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