Discussion in 'Tutorials' started by Selezen, Dec 12, 2012.

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1. ### SelezenMember

Part 1: Planning and Building Your 3D Model

Planning

Before you create any 3D objects, plan out what your end model will be. Find some pictures or photos of it if you can, or if it's a self created item, draw it out on paper or in a drawing app a few times to get a feel for the real 3D shape. Some people make mockups in LEGO or some other building material first.

Once you have a feel for how the model will look and feel, think about what it will be used for. Will it be handled a lot? Will it be a display model? Will it be something to hang on the wall or give to the kids to play with? Each of these options opens up different issues. If it is to be handled a lot (such as a gaming miniature) then it will need to be sturdy and might need internal supports, for example.

I'm using a human-scale model of a LEGO lightsaber handle for this tutorial - the intent would be for it to be used as a prop or a toy, and maybe have a mockup lightsaber blade put on it, or maybe some lights fitted inside. It will therefore need to be quite sturdy. Note that I'm British, but I will be annoyingly consistent in spelling "saber" with the "e" before the "r" because a lightsaber is an American film-maker's invention and the canonical spelling of the word is the American way. Sorry about that, UK readers.

In planning for any prop, durability is to be considered. With this particular model, the fact that it is basically a cylinder means that it will be quite sturdy on its own. Breaking the model down into various sized cylinders (a new complete cylinder for each change in diameter on the model) adds even more sturdiness and makes it a nice, simple, quick build. I like simple.

Step one, then, is to find or draw a 2D flat representation of the model from the three cardinal directions (top, left and front) that are represented by the three main views in Wings 3D. You can obtain bottom, rear and left elevations as well if desired, but for this model they're not necessary. In fact, this model only needs a side view, as the top view is exactly the same and the front view is a cylinder.

Open Wings3D, right click on the empty workspace and select "Image Plane".

Using the dialog, find your side view and select it - it will load into a flat "plane" which will by default show to the X axis. Select the Image Plane, making sure that Object selection mode is active (that's the last of the block of 4 pyramids at the top of the workspace)

Rotate the view a bit (using the middle mouse button with a bit of movement) so that you can see the relative position of the selected plane. Right click in the workspace, select "Move" then "X". Moving your mouse will move the Image Plane back and forward along the X axis. Press "Tab" on the keyboard and type "-10" into the Numeric Input box then press "Enter" - this will move the plane 10 units to the rear (left) of the workspace.

You have the option at this point of scaling the Image Plane to use Wings' grid as a scale guide to the finished article. It isn't actually all that important at this point because the exported texture at the end of this process will be on either a 512, 1024, 2048 or 4096 pixel square and you'll just have to scale it again in your drawing app later. However, on some projects I have been known to create a 1x1 square "inset" in one face of the model to give me a scale guide for later. The idea is to use that square in your drawing app, using centimetres or inches or whatever as your scale, make the inset guide in your model be equal to 1x1 in your drawing later. I won't be going back to this in the tutorial, but you can ask for a few more hints about it later if you like.

This part of the tutorial is more of a quick overview of modelling with primitive shapes in Wings3D. If you already know all this stuff then you should either be able to work through it really easily or just skip it and go to either part 2 or part 3. Up to you really.

Press "Space" on the keyboard or click anywhere on the empty part of the toolbar to unselect all objects. Choose "Select" from the menu and click on "Lock Unselected Objects". This will lock the image plane in place so that it can't be selected using the mouse and leave us free to work on the actual model.

Now to the saber itself. Right click in the workspace and select Cylinder. As if by magic one appears. Switch to Edge select mode (second pyramid on the toolbar) and select all the vertical edges of the cylinder. An easy way to do this is to press "x" on the keyboardto view the model along the X axis and go into orthagonal display mode (second of the icons at the right of the toolbar). Once the edges are selected (there should be 16 of them) right click and select "Bevel". Press "Tab" on the kb and enter "0.095" in the Numeric Input box then press Enter.

Click on the Object mode pyramid to select the whole cylinder. Right click and select "Rotate" then "X" then press the "TAB" key and enter "90" into the Numeric Input box. This aligns the cylinder with the Z axis as shown below (viewing directly along the X axis). Right click, select "Scale Uniform" and resize the cylinder until it is the same height as the drawing behind. As stated, viewing directly along the X axis will make it easier to see when the cylinder is the right size. It doesn't have to be exact.

2. ### SelezenMember

Press the space bar to unselect everything then click on the Vertex selection mode pyramid (first pyramid on the toolbar). Select all the vertices on one end of the pyramid then right click, select "Move" then "Z".

Moving the mouse will move the selected vertices along the Z axis. If you hold down the "ALT" key whilst moving the mouse then the vertices will snap to the grid at 0.1 unit intervals. Move the end you have selected to the appropriate end of the reference drawing on the Image Plane, again using the view along the X axis to check the location. Again, it doesn't have to be exact, but use the "ALT"+Move option if you want. Do the same with the opposite end of the cylinder.

Once you are happy with the shape and size you have a base for the rest of your objects. First we'll make the other short cylinders of the same diameter. Create a duplicate of the original cylinder by going into Object selection mode, selecting the cylinder then right clicking and selecting "Duplicate" then "Z". This will create a new copy of the cylinder and allow you to place it somewhere on the Z axis. For easiness, try to place the centre of the cylinder as near to the centre of the cylinder you want to create next as you can.

Use the scaling tool to resize the cylinder along the Z axis until it is about the right size. Select the end face or vertices and move them to the correct places as we did above. Make a duplicate of this new cylinder and use that to make the third similar sized cylinder until you have something that looks like the pic below (if you're following this yourself, of course).

To create a different sized cylinder for the bigger bits, duplicate again and then right click, select "Scale Radial" then "Z" - this will retain the Z length but make a bigger diameter cylinder.

It's often useful on a card model template to have a guide line where something needs to be attached. We can do this on the 3D model so that the exported template has this already drawn on (saves time later). Go into face selection mode (third pyramid in the middle of the toolbar) and select the front and back (z facing) faces of the larger cylinders - the pic below shows the first of them selected:

Once you have selected the four faces, right click and select "Inset".

Use the mouse to resize the inset to be roughly the same as the smaller cylinders on each side. The image below has the smaller cylinder set to wireframe so you can see what's happening a bit better (yes, this helps).

3. ### SelezenMember

For this model just repeat the above steps and you should finish it off quite quickly, getting to this stage:

I went through a process at this stage of extruding the four greeblies, but it was too finicky for this tutorial and took up about half of the ENTIRE tutorial (not just this part), so I've opted to miss it out. If there's a demand for it I'll include it as an appendix once the main tutorial is done. Images from here will have the first greebly only.

For this model we need two hollow cylinders, one at each end, which is where the "blade" would be inserted on the LEGO model. To do this we will use the Inset and Bridge tools (which are very useful). First, though, the end with the greebly needs to be cut at the end of the greebly to make a separate cylinder of the same diameter. Using the edge selection, cut and connect tools, I cut the edges that did not have the greebly on then lined them up with the greebly's edge using the move and Absolute commands. Once everything was lined up I selected the ring of edges and used the Loop Cut tool on the right click menu to separate the end.

I then used the Object select mode to select each end cylinder. I need to be able to see the ends of each cylinder so I hid the other parts using the "Hide Unselected Objects" tool on the Select Menu.

Now, select each end face using the Face select mode then right click and select "Inset".

In the real world it doesn't really matter how big the hole in the middle is, so pick one that looks aesthetically pleasing. If you have something in mind and need a particular sized hole, use the absolute scale command to specifically size the hole (or use the "ALT"+Move method as outlined above):

4. ### SelezenMember

Wings can only bridge 2 faces at a time, so deselect one pair and then right click and select "Bridge".

Do the same with the other piece and you should get what's below:

You're now finished building the 3D model. Congratulations. You can now delete the Image Plane and unhide the rest of the model. Go to the Select menu and click on Unhide All, then in the same menu click on Unlock All. In Object select mode, click on the Image Plane and press "Delete" on the keyboard.

Once you have done that, it makes some sense to space out the parts so that you can see them more clearly. In this model everything's lined up on the Z plane, so I just spaced everything out on that plane so I could see the interior surfaces a bit more clearly.

That's it for this part, building the model. The next part is quite short and involves how to set the model parts up so that they break apart in such a way as to "map" properly and unfold into a "net" suitable for paper modelling.
5. ### SelezenMember

Part 2: Finalising and Optimising the Model for Card

Now that you have a basic model you have to make sure that Wings can cut the model up into parts that will be suitable for colouring and texturing and (of course) building as a card model.

Wings has a utility called a "UV Mapper" which takes a model and breaks its faces up into 2-dimensional planes that can be stitched together. The most important thing to remember about this utility at this stage is that it uses "hard" edges to split the model up.

So we have our finished and separated out components for our lightsaber after the first part of the tutorial. Now we have to determine how to cut the model up. Simply put, the model needs to be cut into sub-parts that will be easy to flatten out onto paper or card then cut out and build. In the case of this model each cylinder will be comprised of three parts - the top circle, the bottom circle and the outside edge (or circumference).

Use Edge select mode and the Loop Select shortcut ("L" on the keyboard) to select all the edges of the cylinders where (in this case) there are 90 degree angles - note that not all of the relevant edges have been selected here.

Note that in more complex models there will be surfaces and edges that are not at 90 degrees to other surfaces and these will also need to be separated out. The simple rule of thumb to remember is that if an edge is not bisecting a completely flat face then it will need to be turned into a hard edge for separation in the UV Mapper.

Once all relevant edges have been highlighted, right click on the window and click on "Hardness" then "Hard".

Nothing noticeable will happen until you deselect the edges, at which point you will see that the edges have changed colour (in my setup it's blue but in the recent versions of Wings the default is a hideous orange).

In order for the outer edges of the cylinders to be extracted as flat pieces, they have to be given a hard edge to act as a "cut" - to visualise what I mean take a sheet of paper and roll it so that the two edges meet - that meeting of edges is what's missing in our virtual cylinder in Wings. The UV Mapper process will make a real mess of the outer surface if a cut edge isn't included.

Select one edge in each outer surface of the cylinders as shown below. Note that if a cylinder has been split into two or more sections (as the longest cylinder has in the demo) adjacent edges in both sections will need to be selected. Again right click and select "Hardness" then "Hard" to set these as cutting edges. NOTE: for torus shapes (hollow cylinders) as shown at the right of the picture below, a cut edge will need to be created on the inner surface too.

Sometimes, depending on the shape of the model, I find it easier to just make EVERY edge a hard edge so that the UV Mapper utility cuts the model into every component face. Of course, for complex or rounded models that just isn't practical due to the length of time it takes to stitch everything together again manually in the editor, but it's a useful option for simpler models. This is one of the reasons why Wings isn't really suitable for complex card modelling as mentioned before. How many edges you separate is up to you but be warned that this process will take trial and error on your part before you will understand the nuances of using Wings for this.

In order to preserve the relative scale of each part when extracting, it is generally advisable to extract all the components as one combined "object". In order to do that, go to Object Select mode and select everything. Right click then click on "Combine".

Once everything has been combined right click again and select ".UV Mapping" (you may need to highlight the "More" entry if your menu has been truncated).

6. ### SelezenMember

Now you will see a new window titled "AutoUV Segmenting". This shows the model again. For our needs there's no manipulation needed in this window so right click in the window and click on "Continue" then "Unfolding".

After a small amount of thinking (very small in the case of our lightsaber here) Wings will display the AutoUV window. This busy window shows a 2D representation of the parts of our model as dictated by the "cut" lines we added using the edge Hardness tool. If an edge was missed it will look very odd, almost like some sort of Escher design. If all the edge cuts were in the right place, it will look something like this:

Now the fun starts! You will need to join together some of the faces of your design and separate others to make a good template for your card model. The trouble is that I've got to this stage and realised that the lightsaber model is just a series of simple cylinders that don't need much in the way of manipulation in this window in order to make a good template (maybe a bit of rescaling and moving around but that's it).

As a result, I will draw this part of the tutorial to a close and when we come back we'll use a slightly more interesting model to illustrate how to bring parts together and separate others using the AutoUV window to build a good model template.
7. ### SelezenMember

Part 3: Using the AutoUV Utility

In the last part I showed how to divide a simple model into parts that could be exported in 2D to make a template for a paper model. Hopefully you can now use the edge Hardness tool to divide a model up into parts that can be flattened onto a single plane.

This final part will illustrate how to create the "primitives" with which to create a model. Since the lightsaber was far too simple to show anything interesting, I have discarded that model and drawn up a slightly simplified version of the BSS Jane Seymour (from the old computer game of the same name).

The ship is made up of relatively simple primitive shapes and I've used the inset and cut tools in Wings to create the outlines of the engines and some features on the main hull (visible as black lines on the left and centre of the model shown above.

I have cut the ship into distinct structures that can be built separately in the card model then glued together. The coloured diagram below shows how it has been cut up, each different colour denoting a different structure.

The exploded diagram below shows each component more clearly. I've made every outer edge a hard one in this model so that there will be some work to do joining everything together. As mentioned before it's often better to do this with Wings models as the UV Mapper sometimes gets confused with misaligned normals (and I haven't found a way to get round it yet) making it easier to just separate everything out and make sure each surface is accurate before joining it all back together.

As outlined before, the components should be grouped together into one object by entering Object mode, selecting everything, right clicking and selecting "Combine". It is worth right clicking on the object and selecting "Rename" and giving the object a sensible name (something other than "cube1" would be nice).

Right click the object and select "UV Mapping" (remembering that it may not be on the main menu and may be in the "More" item at the bottom).

In the AutoUV Segmenting screen, simply right click and select "Continue" then "Unfolding".

8. ### SelezenMember

A whole mess of stuff will be shown in the AutoUV window. This screen represents every surface of the model. It now needs to be joined up again.

Press the space bar on the keyboard to deselect everything then select the Edge selection mode in both the AutoUV window and the Geometry window. In the Geometry window select the edges that you want to join together. Note that every edge selected in this window will select 2 edges in the AutoUV window - one for each of the two faces that share that edge. In the example below the edge selected happens to be in the same place for both faces in the AutoUV window.

Right click in the AutoUV window and click "Stitch". This will join the two edges together and move one of the faces to join with the other and share that edge. Note that normally only a single shared edge can be joined this way unless the edges are all sharing the same orientation. The long cylinder in part 2 is one such example, as is the top surface of the engine section in the Jane Seymour model.

The rest of this process is the long, laborious and boring part. Each component structure needs to be partially assembled into a logical "net" to build into a model. Stitch the necessary edges together but be careful not to join too many together. Keep an eye on the joined shape in the AutoUV editor to make sure it still looks like a reasonable template that could be cut out and stuck together again. The screenshot below shows the engine section of the Jane Seymour once it has been stitched into a good net (highlighted in red).

The biggest problem with the AutoUV editor is that it is a messy interface. The parts move around as you stitch them together and might jump off the part of the screen that you are using. You can use the middle mouse button to scroll and zoom the window and anything selected or deselected in the Geometry window will be reflected in the AutoUV and vice versa. It just takes a little practice and experience to be able to "see" what's going on in the sometimes cluttered window. The screenshots make it look worse than it is as I tried to keep that working window small. You, however, can make the thing full screen and give yourself more room to move. Don't make the AutoUV window bigger than half the size of the Geometry window, though, or you will limit your ability to tumble the main model and find the parts you are looking for.

I wish there were more words I could think of to describe this process, but sadly the above sums it up. It's just a process of stitching things together - the UNDO feature is your friend here, as you will inevitably make mistakes and join the wrong parts together. Just remember to check your progress by using the AutoUV window's Object selection tool to select your part-in-progress and make sure it looks right.

Of all the tutorial, this is the most lengthy part and the part that will most likely need expansion. If you feel there is more here to be covered, please comment or let me know and I will expand it in either this tut or in a whole new one.

Anyway, as far as the Jane Seymour is concerned, once the stitching and moving was done, this is what the template sheet looked like:

The template is now too big to fit on the drawing area and must be resized slightly to fit. This will happen on templates that are initially cut up without a lot of free space in them - the act of joining together nets will inevitably cause more white space than there was to start with. To resize the templates, select them all in Object mode then right click and select Resize then Uniform.

9. ### SelezenMember

Once the template looks like it will all fit in place, then you can move each piece into its place on the sheet and make sure everything looks tidy and complete.

Now the template can be exported to a bitmap texture image ready to be "coloured in". Right click on the image in the AutoUV window and select "Export Bitmap".

In the interface that appears, select the image resolution that best suits your purpose and the amount of parts that are on the sheet. If there are a lot of parts choose a larger size like 1024x1024 or 2048x2048 (remembering of course that the file will be larger on your disk).

When you click OK on the export window Wings will show the filled in texture image (white background instead of ABC background). Close the AutoUV window and the Outliner window will show the new texture image in its list (identifiable by being named "object_auv" with a thumbnail of the image below it). Right click on that image and select Make External.

A standard load/save dialog will be shown (Windows XP flvour shown here). Make sure to select a file type here, as none is initially selected and BMP will be the defalt type no matter what extension you manually type into the box. I usually go with PNG as Wings does a good job encoding a nice small size.

Click OK and the job is done - Wings has now generated a line drawing of your model template. It's now up to you to apply whatever decorative masterpieces you want to add using whatever drawing package you prefer. I personally use Inkscape.

10. ### SelezenMember

AFTERWORD: It's always worth giving your texture a good once-over before you click that AutoUV "Create Texture" button. It was only as I was checking over the screenshots that I noticed this beauty:

Hmm. Not very professional. If you catch this in the AutoUV editor before exporting then you can cut and restich your model to get rid of this kind of overlap. You could also restructure your model using your drawing package if you didn't catch it in time. Inkscape makes this quite easy as you can use it to trace the outlines and move the parts around easily. But that's fodder for a future tutorial.

I hope this tutorial was useful and goes some small way to giving something back to this fantastic forum and all your amazing work.