A 3D editing plugin

Blender survival guide

Blender survival guide to render .shapes and .dxf files generated from A_3D_editing plugin for ImageJ.

News 2005-12-01

The CurveMorphing python C module is available for download as a beta. The module provides the ability to generate MUCH better, almost perfect skins around any set of bezier curves, and create weighted interpolated curves in between if desired.
An updated Blender plugin for loading .shapes files is available, fixing long unsuspected issues with bezier curves, introducing a new skin generation method based on the CurveMorphing module, and introducing the ability to (finally) use the 'df' density field option in the java ImageJ plugin.

Tutorial

0- Open Blender 2.36. (2.35 will work too for this tutorial, as the undo feature was added then. Any later version as well). Fetch Blender if you don't have it. It's a free, open source program.

1- 'F1' and select your .dxf file. To navigate folders: folders are clustered at the top of the list and are highlighted in white. To go to the parent folder, click on the '..' folder. Middle-click on the .dxf file to open directly; alternatively, left-click on the file and the push the "open" button. If the file is large (10 MB or more) be ready to wait about a minute or more.

If the file has loaded only partially, it means it was generated with errors. This usually means there are one point pipes in the model which fail to be dxf-ed properly. Remove them and generate the .dxf file again.

2- Where's the object? Usually it is way too large and you have to zoom out. To do so, the easiest is to use the mouse scroll wheel. If you're on a Apple laptop with one single mouse button, then do control+option+drag. Help on MacOSX one-button mouse limitations can be found here.

3- Right click on an object to select it. On an apple laptop, apple+click. The menu that (may) pop up showing information on location, rotation and size of the object can be toggled on and off by pushing the 'n' key. Your selected object will look as a white wireframe.

You can also select several objects by holding shift while right-clicking more objects.
Further, push 'b' and then click+drag to do box-select. This will select several objects.
Deselect all selected objects anytime by pushing 'a', or inidivual ones by shift+right-click.

4- You can switch with the 'z' from wireframe to solid view and back. Alternatively, use the little pulldown menu (the second from the left, after "View Select Object" menus).

5- 'F9' to go to the editing buttons. Below the 3D view you'll see two menus.

6- 'TAB' to enter edit mode. Below, 2 new menus are visible to the right so there are 4 now. Your selected object will show its points as either pinkish or yellow. Push 'a' to select all points; if any where selected before, 'a' will deselect all selected points, so push 'a' again to select them all.

7- In the third menu below ("Mesh Tools"), push "Rem Double". Alternatively, keep the mouse on the 3D view and push 'w', and select "Remove Doubles" from the popup menu.

Now your object, which was made of separate, vertex-overlapping triangles, has been transformed into one big mesh.

8- In the first menu below ("Link and Materials"), push "Set Smooth". This will recalculate the normals of the faces of the mesh and show it smooth. Push 'z' to enter "Solid" view (or select from the pulldown as explained above) and also push 'TAB' to exit edit mode. See how the selected object looks better.

9- Since the "Set Smooth" is usually not enough, push 'TAB' to reenter edit mode. If all points show yellow, that's it, they are still selected. Otherwise push 'a' once to deselect and 'a' again to select all points. Then, from the "Mesh Tools" menu below (remember we have pushed 'F9' to display the editing buttons before) click once on "Subdivide". Then click from 1 to 5 times on "Smooth". The object will be smoothed!

10- Undo: within edit mode (when all points are displayed as pink -deselected- or yellow -selected) typing 'u' with the mouse in the 3D view will undo whatever you've done.

From outside of edit mode, alt+u will popup a list of all actions. The last ones are at the bottom-right.

11- For normal Blender usage, having the objects so large is unconvenient. They can be resized anytime by selecting the object (or objects, hold 'shift' while right-clicking more objects) and then pushing 's' and dragging the mouse towards the center of the object.

12- For most convenient manipulation, push 'numpad-1' and zoom out until you see a vertical blue line and an horizontal red line. Left-click at the intersection of both lines. Then push numpad-3 and again left-click at the intersection of the vertical blue and horizontal green line. Then you have the cursor (the big floater) at the middle of the 3D space. Now, rigth-click on any object to select it if it wasn't already, and then do 'shift-s' and select "Snap selection to Cursor".

Now our object will be situated at the middle of the 3D space.

13- You can click at 'c' to center the view on the cursor. This is most convenient, so now you can zoom in (mouse-wheel) to see the maximum of your object.

14- Rotation: click+drag on the mouse-wheel (middle-drag). On an apple laptop, do option+drag. Fixed rotation can be done horizontally by numpad-4 / numpad-6, and vertically by numpad-2 / numpad-8.

15- Changing the color of the object: right-click on an object to select it. Then, push 'F5' to access the shading buttons in the panel below. Click on the red ball button next the light bulb if it is not already selected.

The objects imported from the .dxf file will have already an assigned material. You may simply adjust their color by clicking, in the "Material" menu (second from the left) on the colored box next to the "Col" box, and there selecting the color. Alternatively, drag the RGB sliders.

Transparency: the "alpha" value underneath the RGB sliders. 0 is 100% transparent, 1 is opaque. For the transparency to have any effect you must click on the "ZTransp" button on the "Mirror Transp" menu, to the right.

Light emission: to the right, on the "Shaders" menu, you can change the "Emit" value from 0 to 1, so the object will shine.

Texture: on the right most panel ("Texture"), click on "Add New". Click on the "TE:Tex" box to rename the texture. Then push 'F6' to show the texture buttons. Our texture is already selected. Select one type of texture on the "Texture Type" pulldown menu that says "None". Experiment with them, they can be both very simple and complex.

You may assign any one material to any number of objects. Simply select the object you want to assign the material to, and then in the 'F5' menus select that material from the pulldown menu under the "Material" menu.

16- Lights: by default Blender adds one single light. It appears on the screen as a yellow circle with a yellow dot in it, and a dotted line runs from it to the standard xy plane. Select the light by right-clicking it and then go to the 'F5' menus, the ligh bulb button. There you may adjust the "Energy" slider (second menu from he left) and the type (Lamp, Area, Spot, Sun, Hemi). The 'Lamp' should be ok.

update:It is much easier to use 'dupliverts' to make a spheric vault of dim lights. Create a sphere with space bar - add - mesh - icosphere (2 subdivisions is fine). Push 's' and drag the mouse away to resize the icosphere so that it is larger than the objects to cast light on. Then push 'TAB' to get out of edit mode, and while the cursor is still at the center of the icosphere (otherwise right-click the icosphere to select it and do shift+s "cursor to selection" to place the cursor in the middle of the icosphere) do space bar - add - lamp - lamp. Then, while the lamp is selected, hold shift and right-click the icosphere to select it, now both are selected, and do control+p to "make parent". The icosphere is now the parent of the lamp. Select the icosphere alone, go to the object buttons 'F7' and click on 'DupliVerts' (to the low left of the screen). Done! Every vertex of the icosphere is now a dim light bulb, generating a very nice ambient light. Make sure the light is really dim, like 0.04, by selecting it and going to shading buttons 'F5' and adjusting its energy slider. Note: dupliverts work with any object. This is a very easy way of making a single object and displaying it following a specific pattern given by the parent mesh (any mesh will do).

You can duplicate a selected lamp by alt+d. This will make a linked copy, so adjusting the settings of one lamp will adjust the other too. Alternatively do shift+d to make an independent copy. Once duplicated, the copy is selected and you may drag it around by dragging the mouse. Click to drop it.

A trick I use to generate nice ambient light is to add one dim light (energy = 0.040; you can click on the "Energy" slider to type in the exact number) outside the object and generate several copies around the object. To do this, place the lamp outside your objects. Select all your objects (excluding the lamp) and then shift+s, and select "Snap Cursor to Selection". Now select, from the third pulldown menu after "View Select Object", the "3D Cursor". This is useful to rotate, scale, etc objects relative to the position of the 3D cursor, which is now centered on our objects of interest. So, now do numpad+7 to go to top view and right-click the dim lamp to select it. Push 'alt+d' to make a linked copy of it, and push 'Esc' to avoid dragging it around. The lamp copy will be selected. Click 'r' and hold 'control' while you drag the mouse, so that the copy will move away from the original lamp, and rotate it exactly 45 degrees (holding 'control' makes this a precise operation). The number of degrees is shown on the bottom left of the 3D view. Repeat until you have a full circle of lamps. Now select all lamps (shift+right-click each, or use box select -the 'b'- from a side view such as numpad-3) and from the side view (numpad-3 or numpad-1), do an 'alt+d' to duplicate all 8 lamps. Drag them upper or lower. Repeat as many times as needed, to generate 3 or 4 layers of dim lamps. This will generate very nice ambient light.

Finally, add a new lamp by left-clicking where you want it, and then 'space' -> Lamp -> Spot (remember to keep the mouse within the 3D view or the key bindings won't work). The lamp spot direction can be rotated by 'r' from any of the top (numpad-7) and side views (numpad-1 and numpad-3), so the light is beamed at the object of interest.

17- Set the background color. This is referred to as the "World". Under the materials buttons ('F5'), click on the rightmost icon, a blueish ball. "Ho" is Horizon color, and "Ze" is zenit colors. Both can blend if the "Blend" option is chosen (it's a button on the left side). "Amb" is the ammount of ambient light, to get blurring effects. Clicking on the color box will popup a color picker window as in the materials.

18- Take a picture! Push 'F10' to show the Scene buttons. The Render will show you what the camera is looking at. The numpad-0 will show the camera perspective. This will almost for sure be wrong. The camera that Blender has set by default can be safely ignored, selected and moved, deleted ('x'), and so on, as any other object.

The easiest is to add a new camera. Rotate the view (middle-drag, or option+left-drag on Apple laptop) until you see the model the way you want to. Left-click to place the cursor where you want the camera. 'space' -> Camera to add a new camera (if nothing happens, make sure the mouse is within the 3D view). Any added object will show as selected. 'control+numpad-0' to make the selected camera the active camera. The view will change to the camera perspective. The depth may not be appropiate, so rotate the view until you see the camera perfectly from the side, then 'g' to grab it further away from the object (you may need to zoom out for this). 'numpad-0' to see what the camera sees. See the object as solid to better appreciate it ('z' toggles wireframe/solid).

Then go to the 'F10' Scene menus and buttons below the 3D view. For a good render, in the "Render" menu choose OSA (antialias), 16 bit, 100%. In the "Format" menu choose Jpeg from the pulldown file format menu, and Quality 100 (drag the mouse in the "Quality" to increase it, or click it to type in the value). The SizeX and SizeY determine the size of the picture to be taken; 1024x768 may be enough, but can be set many times this size. Push the large "RENDER" button (or 'F12') and wait.

A popup will appear. When the image is done, 'F3' to save it. Otherwise 'Esc' to return to your model and adjust it. Be sure to add the .jpg extension to the name.

A tip: render is by default with perspective, but you can render in non-perspective, i.e. orthographic mode. Select the camera and push 'F9' to see the editing buttons. On the right, click at the "Ortho" button. There you may also change the properties of the lens.

19- Save everything! From within the 3D view, push 'F2' to save the model as a .blend file. It is much more compact thant the .dxf file and it will hold all the adjustments in size, materials, etc, that you've done. Write the .blend extension yourself or it won't be placed there. Whenever you reopen this file, it will look exactly as you last save it.

20- There is much more to Blender. At the bottom left of the 3D view window you can select several other windows, for instance the "Scripts window". There you'll find python scripts that enable useful things such as cutting an object in two (the knife tool for meshes) and so on. Experiment!

21- The windows can be split, so you can look at a model from several directions at the same time. Move the mouse and middle-click at the edge of a window. A popup will prompt for either splitting or joining the windows. Whenever you screw up things too badly, control+up_arrow to return to a standard set of window views.

General commands:

Select an object: right+click to select it. Shift+right-click to select more objects (or deselect a selected object among several selected objects). 'a' to select all, and 'a' also to deselect all when any are selected. Also, 'b' to do box select: drag, and click to finish.

Moving objects: right-click to select, then 'g' to grab it. Drag the mouse and click to drop it.

Rotating objects: 'r' and drag, click to finish.

Scaling or resizing objects: 's' and drag, click to finish. You can constrain the direction of deformation by pushing x, y, or z, and also by middle-clicking and dragging towards the direction you want.

Delete object: 'x' and confirm the dialog.

Tips

How to remove doubles and smooth all objects at once

Whenever there are lots of objects, it becomes tedious to select each one, remove doubles and set it smooth. Here is a workaround:

1 - Give each object the color you want.

2 - Select all objects by 'a', or by box select ('b').

3 - Type 'control+j' to join all objects in one big mesh. Colors (the materials of each individual object) are preserved for each old object (which is now a group of vertex within the larger object). If you have lamps and others, you may have to deselect them before joining the objects.

4 - 'TAB' to enter edit mode, 'a' to select all points (so they look yellow) and 'w' to remove doubles.

5 - 'F9' and push the 'Set smooth' button at the lower left of the panels.

WARNING: if more than 16 objects are merged, any object added beyond this 16 object limit won't have its color preserved. This is due to a 16 materials per object limitation in Blender. All the above can be automated without merging any object at all by using the "Remove doubles and set smooth" plugin.

How to split two merged objects

1 - Select the merged object.

2 - 'TAB' to enter edit mode.

3 - 'a' once or twice, to deselect all vertices (so they look pinkish).

4 - Select the points of the object you want to separate, by 'b' (box select) or right-clicking each one.

5 - 'p' to part, to separate the selected vertices into a new mesh object.

6 - 'TAB' to exit edit mode, and now right-click to select the new object and edit it.

How to make copies and display them following a pattern: DupliVerts

1 - Create a mesh, any will do.

2 - Create or select the object to be duplicated in a pattern (Above a example with lamps to generate ambient light is explained).

3 - Make the mesh the parent of the object to duplicate. This is done by selecting the object first, then with shift+right-click selecting the parent mesh, and then control+p "make parent".

4 - Select the parent mesh and go to the object buttons 'F7' and click in 'DupliVerts'. In every single vertex of the mesh, the child object is duplicated.

5 - Adjustments: the child object copies may be displayed with an offset to the vertices of the parent mesh. To adjust this, move the child object to the center of the parent mesh; this can be automated by selecting (right-click) the parent mesh, shift+s "cursor to selection", then selecting the child object and shift+s "selection to cursor".

Plugins for Blender

How to install and run Blender plugins

Unzip and drop the plugin file into Blender's scripts folder.
In MacOSX, this folder is hidden inside the Blender.app . Control+click it and select "Show Package contents". Navigate to Blender.app/Contents/MacOS/.blender/scripts folder and drag and drop the file there. Update: the above won't let you open the folder .blender because macosx interprets files and folder names starting with a dot as invisible. This way works: in the finder, Go->Go to folder... (or push shift+apple+G) and type the directory there: /Applications/Blender-2.36/blender.app/Contents/MacOS/.blender/scripts , then drop the plugin there.

To run the plugins: At the lower left corner of the Blender 3D window there is a pulldown menu that let's you switch windows. Select the top one; it has a green snake (python's logo). Then, next to this lower left pulldown menu you'll find a "Scripts" menu. From there navigate to the desired plugin.

Alternatively, one can select a text window, open the plugin and do alt+p to run it. This is very useful to write and setup plugins.

Plugins

Remove doubles and set smooth
Load the DXF file, push 'a' once or twice to select all objects, and then run this plugin from the Scripts - Mesh submenu. Only mesh objects will be processed.
Load .shapes file directly into Blender.
Load the .shapes file right into Blender, without any need to generate a DXF file. A real time and space saver!
The script will appear under Scripts / Import / Import shapes v1.1 (drop it in the /.blender/scripts/ folder first!)
Version 1.1 sets the center of the object to the center of the bounding box of the object, for convenience. Also some minor internals have been fixed.
Version 1.4.3 introduces the ability to create almost perfect skins with the CurveMorphing C python module. Also, any given number of interpolated curves can be created for each z level, an further, if a curve is missing at any z level, the program will automatically interpolate one in place. View the CurveMorphing module specifics for all details. You NEED to download and install the CurveMorphing module for such functionality to be available, otherwise only the old 'static' skin-making method will be.
Set the material of the active object to all selected objects.
In Blender, when selecting multiple objects with shift+right-click, all objects are highlighted in pink except for the last one that was selected, which is highlighted in white because it is the active object. With this plugin, the color ("material" in Blender jargon) of this active object will be assigned to all selected objects.
The plugin appears under Scripts / Materials / set material to multiple objects (drop it in the /.blender/scripts/ folder first!).

Links

Modelling links:

Blender documentation:

Hot keys, window reference, buttons reference.

Python scripts links: