Intro to 3d mesh modeling in Blender

Blender is a free, open source 3D graphics application that can be used for modeling, texturing, rigging, animating, rendeing, simulating physical interactions and creating interactive 3D applications, including video games, animated film, or visual effects.  Download at: http://www.blender.org/

We will be using version 2.49

Quick Start notes:

Mouse:

  • LMB :  Left Mouse Button
  • MMB:  Middle Mouse Button
  • RMB:  Right Mouse Button

3d Viewports – right side alpha numeric keypad:

  • 7 = top view
  • 1 = front view, 3 side view
  • 4 + 6 = rotate around
  • 5 = toggle between perspective and orthographic views

Navigating:

  • Zoom:  hold Ctrl and click drag with MMB, or use MMB scroll wheel
  • Pan:  Hold Shift and MMB
  • Rotate view around:  MMB and drag
  • “.” to Zoom in on a selected Object

Spacebar = main menu options

Menus:  All Menus in Blender are ‘zoom-in-able’ (rendered in open GL)

3d modeling – Shortcut keys

  • Tab:  Toggle between Object and Edit Modes
  • A” toggles between de/selecting everything
  • B” brings on window selection mode – hit “B” again to bring ‘brush’ selection mode
  • RMB to select geometry, ESC to cancel
  • R” – Rotate
  • G”  – Grab / Move
  • S” – Scale
  • E” to extrude a face (must be
  • For any command, to lock the operation to an axis, type X, Y or Z as required
  • Duplicate:  Shift D

Let’s start a simple modeling exercise:

1:  Start with the default Blender cube.  The default cube is 2 x 2 x 2 units in size.

2:  Hit Tab to enter Edit Mode, hit “A” to select all the geometry

3:  Click “R” for Rotate, then “Z” to lock rotation in the Z Axis only.  Type “45” to rotate the cube 45 degrees.

4:  “A” to select all geometry, them “Shift D” to Duplicate.  Hit Y to lock movement in the Y-axis.  Hit “5” then “Enter” so that the new, duplicated cube is 5 units away from the original cube.

5:  Repeat these steps, duplicating the cubes in the X Y Z axis until you get an array of cubes

6:  Its starting to look a bit busy, so toggle the ‘occlude background geometry’ button so that this:

looks like this:

Occlude background Geometry Toggle

Occlude background Geometry Toggle

7:  Make sure you’re in “Face Select Mode“, Select two cube faces to join (Hold Shift to select multiple things)

8:  Hit “F” to create new faces between the two selected faces.  Choose the “Skin faces/Edge Loops” Option

new faces are created between the selected two faces

9.  You’ll see that the new faces have a weird gradient fill to them.  This is because the mesh faces are by default set to “Smooth”.  To keep it consistent with the other cubes in the model, we need to set them to “Solid”.  To to this, hit the “Spacebar” key -> Edit -> Faces ->Set Solid.  You can do this as you create new faces step by step, or you can do it for everything at the end.  Either way, you need to make sure the model is consistent, otherwise you’ll run into lemons when we start smoothing the mesh model.  Take note, you’ll see what I mean….

Spacebar -> Edit -> Faces ->Set Solid

Setting faces 'solid' makes them consistent with the rest of the model.

10:  Now we’re going to split the new faces so that we’ve got more faces.  To do this, Hit “Spacebar” -> Edit -> “edges” -> “Loop subdivide“.  Or just hit “Ctrl R

"Spacebar" -> Edit -> "edges" -> "Loop subdivide". Or just hit "Ctrl R"

Use the Middle Mouse Scroll wheel to increase the number of Loop cuts:

11:  In “Face Select Mode”, select the 4 faces as shown (Hold Shift, RMB)

12:  move the faces “G” for Grab.  Or Scale using “S“.  Or Rotate using “R“.  Or all of the above.  You choose.  Remember if you want to limit the transformation to a certain axis, hit X, Y or Z while you’re running the Grab/Scale/Rotate.

"G" for Grab (Move) Faces

"R" for Rotate

"S" for Scaling

13:  Select a face, hit “E” for Extrude.  By Default it will extrude in the direction Normal to the surface of the face that you select.   What is a ‘Normal’ you ask?  Shame on you, didn’t you do year 10 maths?  Sigh.  Click here for the definition.

Extruding a face, "E", by default extrudes in the direction normal to the selected surface face.

14:  Again, to extrude along an axis, hit X/Y/Z.  You can also type in a number for the length of the extrusion, or just eyeball it and LMB.

15:  Use a combination of these commands to link all of the cubes into a lattice.  Take care to minimise ‘crashes’.  To summarize:

  • F” to create new faces between a selection of faces
  • Ctrl R” to split existing faces into more faces.  Middle mouse scroll to increase/decrease the number of loop cuts.
  • G” for Grab.  Scale “S“.  Rotate “R“.  hit X/Y/Z to lock transformation in an axis.
  • E” for Extrude.
  • Typing numbers gives precise grab/scale/rotate/extrudes.

16:  Avoid messy modeling!

17:  You can also add new objects to the model by clicking where you want to add something LMB, then Spacebar -> Add -> Cube/Plane/Sphere/etc

Add New objects: Spacebar -> Add -> Cube/Plane/Sphere/etc

18: Once you’ve got all the geometry connected in some weird way, check that all the faces are “Solid” not “Smooth”.  You can see here that some are one or the other:

connected geometry has a mix of "Smooth" and "Solid" faces

To fix this, hit “A” (Select All), then Spacebar -> Edit -> Faces -> Set Solid.  or “Ctrl, F, 4

Convert to solid faces: Spacebar -> Edit -> Faces -> Set Solid. Or "Ctrl, F, 4"

19:  Select all faces (A), then Spacebar -> Edit -> Edges -> Bevel.  or “W, Alt, 2

Spacebar -> Edit -> Edges -> Bevel. Or "W, Alt, 2"

20:  Hit “Tab” to Exit Edit Mode

Hit "Tab" to Exit edit mode

21:  Now we’re going to smooth our geometry, using a Modifier.  Click “Add Modifer” -> “Subsrf”.  The Default modifer is a “Catmull-Clark” smoothing algorithm, which is a classic surface subdivision smoothing algorithm (click here for wiki info).

22:  to make your geometry smoother, increase the “levels”.  Level 4 is probably enough, you can take it higher but be warned, your computer may chuck a hissy-fit and crash.  Always good to save your file before doing any smoothing operations.

Level 4 Catmull Clark subsrf smoothing

23:  If your geometry is looking a bit blob-ugly like it is in this example, you can get some nicer smoothing action by adding a “Smooth” modifer before the “SubSrf” Modifier.  To do this, delete the “SubSrf” we just added (click the little ‘X”) and Add Modifier -> Smooth.  Try having a Factor of “1” and Repeat of about “8”.  Increasing the number of repeats increases the “relaxation” of your geometry’s vertices.  After putting this “Smooth” modifier, add the “SubSrf” Catmull Clark Again.

Smooth Modifier at Factor 1, with 8 Repeats

combination of Smooth and Subsrf modifiers

24.  Save your file as a Blender file.  You’ll also need to export your geometry so that we can bring it into Rhino for some more tweaks.  File -> Export-> WavefrontOBJ.

Exporting to OBJ format

1: Type your filename here. Make sure to use .obj extension. 2: Click Export

1: Make sure "Apply Modifiers" is selected. 2: Click "Export"

All done in Blender!  Lets bring it into Rhino.  Type “Import”, Check that “Files of Type” is set to “Wavefront OBJ”, locate the file you exported from Blender.

Impoting the OBJ from Blender into Rhino.

You can see from the Rendered view that it looks like some of the bits are broken.  This is because not all the faces of the mesh are orientated the right way.  To fix this, select the mesh, type “UnifyMeshNormals”.

Thats all for now, will go into more next class….

Blender blobs

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