<h1>MM3D Tutorial - Modeling Geometry </h1>

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      <p>
      </p>

      <ul>
         <li> <a href="olh_tutorial_geometry.html#gettingstarted">Getting Started</a> </li>
         <li> <a href="olh_tutorial_geometry.html#creatingbasicshapes">Torso -- Creating Basic Shapes</a> </li>
         <li> <a href="olh_tutorial_geometry.html#detailadjustments">Torso -- Detail Adjustments</a> </li>
         <li> <a href="olh_tutorial_geometry.html#combiningshapes">Torso and Legs -- Combining Shapes</a> </li>
      </ul>

      <hr/>

      <a name="#gettingstarted"></a>
      <h2>Getting Started</h2>

      <h3>Introduction</h3>
      <p>
      This tutorial will demonstrate how to use Maverick Model 3D. The example
      model will be a humanoid character with texture maps and animations.
      The model will be aimed at an eventual MD3 export, because this
      demonstrates nearly all of Maverick Model 3D's capabilities.
      </p>

      <p>
      Note that I am not an artist--neither 2D nor 3D, so my 3D model
      creation skills are somewhat limited. This fact should be obvious
      by the time you see the finished model. Also note that I am taking
      some short-cuts in the interest of producing this tutorial more
      quickly. There are several places where spending more time on
      detail would provide better results; but my goal was to finish
      this document rather than create a refined example of 3D art.
      </p>

      <h3>Meta Data</h3>
      <p>
      The first thing I'm going to do is open up the
      <a href="olh_metawin.html">Model Meta Data Window</a> from the
      Model menu. The Meta Data Window allows you to enter some
      non-rendered information about the model. In this case I'm just
      going to note my own name in a copyright string by clicking "New",
      then double-clicking on the row to edit the key and value.
      </p>
      <!-- FIXME need year in copyright string? -->

      <p>
      In this instance the meta data is entirely optional. You can enter
      any sort of information you want in this window, or leave it completely
      empty. In some cases, meta data is used by import or export filters
      to track format-specific data that Maverick Model 3D's model class
      doesn't understand (for example, skin path information in MD3).
      </p>

      <h3>Background Images</h3>
      <p>
      Next I'm going to add a
      <a href="olh_backgroundimagedetails.html">background image</a> to my
      forward-facing viewport to aid in constructing the humanoid model. In
      this case I'll be using DaVinci's &quot;Proportions&quot;. Often you'll
      want to use a reference object with images from multiple angles so you
      can get a better sense of width and depth.
      </p>

      <p>
      The model is not intended to look exactly like DaVinci's work, it's
      just a rough guide.
      </p>
      
      <p>
      The background image window has a tab for each viewport direction.
      In my case, I'm just selecting the Forward tab and selecting
      an image file.
      </p>

      <hr/>

      <a name="#creatingbasicshapes"></a>
      <h2>Torso -- Creating Basic Shapes</h2>

      <h3>Pick a Starting Shape</h3>
      <p>
      When creating a 3D object, you will usually start with one of the basic
      creation tools (cube, ellipse, cylinder, or torus). From there you can
      move vertices around to get the basic shape right and split edges or
      extrude to add detail.
      </p>

      <p>
      For our humanoid model, a cylinder is roughly the right shape for all the
      large geometry components. Expect to see many of those.
      </p>

      <h3>Reshaping Geometry</h3>
      <p>
      I am starting with the torso, so I will create a cylinder for that.
      Cylinders are always created horizontally with respect to the viewport
      in which they are created. So after creating this cylinder I need to
      rotate it vertically. If you hold the shift key down while rotating,
      the rotate tool will rotate in 15 degree increments. This makes it
      very easy to get the cylinder perfectly vertical.
      </p>

      <!-- FIXME talk about selection operations here? -->
      <p>
      Now I want to use the Front viewport background image as a reference
      to relocate vertices.
      The selection tools allow you to select portions of the model.
      There are selection tools for vertices, faces, material groups,
      connected meshes, etc. You start a selection operation with the
      mouse button, and use the bounding box to select the region 
      that contains the geometry you want to select.
      </p>

      <p>
      The left mouse button selects geometry, the right mouse button
      unselects. If you press the left mouse button alone, all selected
      portions of the model will automatically be unselected. If you
      hold the shift button the current selection will remain selected.
      The right mouse button never clears the current selection.
      </p>

      <p>
      I use the <a href="olh_tools.html#select">Select Vertices</a> tool to
      select the vertices for the upper body and use the
      <a href="olh_tools.html#scale">Scale Tool</a> to resize that section all
      at once. Then I select vertices down the sides and move them to match the
      outline of the image.
      </p>

      <p>
      Next I use the side viewport to adjust the vertices in the Z (depth)
      axis, which isn't possible from the Front view. In this case the X
      (width) axis and Y (height) axis are correct. So I want to be careful
      to only move the vertices left or right in the Side viewport.
      If I hold down the shift key while using the
      <a href="olh_tools.html#move">Move Tool</a>, the move
      tool will only move on one axis--the first axis it detects motion on.
      </p>

      <hr/>

      <a name="#detailadjustments"></a>
      <h2>Torso -- Detail Adjustments</h2>

      <h3>Edge Turn</h3>

      <p>
      Of course vertices are not the only things to be concerned with when
      shaping the geometry. The faces themselves need attention too. Note
      the highlighted faces near the base of the torso in the image. The edge
      where the faces meet forms a concave angle on the outside of the
      geometry. A convex angle would look more correct. We can fix this with an
      <a href="olh_commands.html#edgeturn">Edge Turn</a>. This rotates the
      edge from the two shared vertices of a face to the two opposite vertices.
      </p>

      <p>
      If you do any significant work in a 3D model editor, you will make
      regular use of the Edge Turn feature. If you are just starting out
      with 3D modelling and the faces look wrong even though all the vertices
      seem to be in the right place, it is probably because you need some edge
      turns. Occasionally you'll need a sequence of edge turns. Note that
      edge turns do not preserve texture coordinates, so you'll want to make
      sure your geometry is mostly where you want it to be before you
      starting applying a texture map to it.
      </p>

      <h3>Edge Divide</h3>

      <p>
      The basic torso shape is in place, but it looks a bit angular on
      the sides. To fix this I'm going to split faces by doing a series of
      <a href="olh_commands.html#edgedivide">Edge Divide</a> operations.
      If you have two vertices selected, and do an Edge Divide, it will
      add a vertex between the two vertices and split any triangles that
      use that edge into two triangles.
      </p>

      <p>
      I mentioned above that you select the vertices of the edge to split.
      Selecting the edge would be more intuitive, but edges are not first-class
      objects in Maverick Model 3D, so there isn't a way to select the edge.
      However, you can select a face that uses the edge and then unselect
      the odd vertex that isn't on the edge you want to split (use the shift
      key with the select tool to unselect selected geometry).
      </p>

      <h3>Snap, Weld, and Hide</h3>

      <p>
      I'm splitting some edges, but I'm also
      <a href="olh_commands.html#weld">welding</a> some vertices back together.
      Welding vertices causes two or more vertices selected vertices that
      are near each other to become one vertex. This may cause some triangles
      to be removed implicitly (if a triangle has an edge with two vertices
      that are welded, the triangle becomes invisible and is unecessary).
      To get the vertices lined up I'm using the
      <a href="olh_tools.html#snapto">Snap to Vertex</a> feature.
      Alternatively you could use the
      <a href="olh_commands.html#snap">Snap Together</a> command. The Snap
      Together command has welding and non-welding versions.
      </p>

      <p>
      While I am working on one side of the model, faces from the other
      side are visible in the same viewport and are distracting, so I
      use the <a href="olh_commands.html#hide">Hide</a> command to 
      make that portion of the model invisible. While hidden, the geometry
      still exists but it is not drawn and it will not be modified except
      under some specific circumstances. Some hidden faces may share
      vertices with unhidden faces. If you move those shared vertices the
      hidden faces will be modified.
      </p>

      <h3>Boolean Operations and Flipping</h3>
      <p>
      Now that one side looks good I want to make the other side match it.
      I could repeat all the work I did on the opposite side, but I'd
      rather not go through that effort. What would be easier would be
      to cut the torso in half, duplicate the side that I've finished,
      and then mirror it so that both sides are identical.
      </p>

      <p>
      Here I use the <a href="olh_boolwin.html">Boolean Operation</a> panel
      to cut the torso in half (read more about boolean operations if 
      the following doesn't make sense). I will set the torso as Object A and
      subtract a cube from the torso. I use the
      <a href="olh_commands.html#simplifymesh">Simlify Mesh</a> command
      to remove faces that don't add detail.
      </p>
      
      <p>
      Then I remove the faces that will be inside the torso since they won't be
      visible. Finally I <a href="olh_commands.html#duplicate">Duplicate</a>
      the half of the torso and <a href="olh_commands.html#flip">Flip</a> it.
      I select the vertices down the middle and use the
      <a href="olh_commands.html#weld">Weld</a> command to join the torso
      together again. Note that weld only welds vertices that are extremely
      close, so I can weld all the verticies in one operation.
      </p>

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      during animation?), also -->

      <p>
      If you're thinking that this use of
      <a href="olh_boolwin.html">Boolean Operations</a> is a bit contrived,
      I agree. Boolean operations can work with much more complex objects
      than what I have shown here, but this works well as a basic example.
      </p>

      <hr/>

      <a name="#combiningshapes"></a>
      <h2>Torso and Legs -- Combining Shapes</h2>

      <p>
      I'm ready to start working on the legs. Before I do that I want to
      adjust the depth of the torso. Assuming that the depth of the torso
      is about the same as the width of the upper leg, I'll use the same
      background image in the side view as the front view, then I'll
      scale the depth of the torso until it looks about right.
      </p>

      <p>
      For the legs, we'll start with the left leg and plan to duplicate it.
      First I create a cylinder, this time with more sides since I ended
      up increasing that with the torso manually. Again, the tool creates
      the cylinder horizontally, so I shift-rotate it to vertical.
      Then I'll scale it to be roughly the right proportions for the
      leg reference.
      </p>

      <p>
      Now I connect the leg to the torso. I remove the faces on the bottom of
      the torso and the top of the leg where the two will connect. I use
      snap to vertex with the move tool to connect the vertices. Then I use
      weld to fuse the two meshes into one.
      </p>

      <p>
      I need to do an edge turn to make the angles look right. Finding the
      right faces to select in the orthographic side and front projections can
      be tricky. So instead, I flip the perspective view into an orthographic
      projection and use that projection to select the faces. Then I flip
      back to perspective to make sure the right faces are selected. Finally
      I do the edge turn.
      </p>

      <p>
      Now I move the leg vertices in the side view to match the leg in the
      background image. Note that the reference image has the leg twisted
      to one side, so this should be pretty close to the expected final
      results. The process for using the background image as a reference
      for the vertices is the same as for the torso.
      </p>

      <p>
      Now I need to add a foot. Rather than creating a separate piece of
      geometry and welding it on, I will extrude existing faces on the leg
      into a foot. The extrude feature is available as an interactive
      <a href="olh_tools.html#extrude">Extrude Tool</a> and an
      <a href="olh_commands.html#extrude">Extrude Geometry Command</a>.
      I will be using the tool version here.
      </p>
      
      <p>
      First I extrude the bottom faces to make segments for the ankle and heel.
      Before extruding the foot itself I move some toe-side leg vertices
      up to the ankle and use
      <a href="olh_commands#snap">Snap Nearest and Weld</a>.
      Then I extrude the front faces on the ankle/heel to make the foot.
      Finally I move the foot vertices around a bit to make the foot look
      more... foot-like.
      </p>

      <p>
      Zooming out a bit, the leg looks somewhat curvy. I adjust the leg
      vertices to take some of the curve out.
      </p>

      <p>
      Now that the leg is in pretty good shape, I want to duplicate it
      for the right side. This is just a simple matter of select, duplicate
      and flip. Because the torso is symmetrical (and I didn't move the
      torso vertices to connect the leg) all I need to do to fuse the
      meshes together is select the vertices on the seam and weld them
      together.
      </p>

      <p>
      Now that I have two legs, the model looks pigeon-toed. So I'll adjust
      that now.
      </p>

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