Taylor's Blender Tips

NEW! Youtube video that explains how to most simply go from point cloud to 3D printable object

(if you do not want to read all of this page, watch the following clips)

part 1:

http://www.youtube.com/user/taylorsgoodman?feature=mhum#p/a/u/1/wM52RaM6sTo

part 2:

http://www.youtube.com/user/taylorsgoodman?feature=mhum#p/a/u/0/Ag-cP-tiO1k

Written Instructions:

The following steps should help you go from point cloud to a simple 3D printable object.
I find this method to be the easiest way to make a printable object; other options are to take several scans (from different angles of the mesh) and mesh them together to get the complete 3D model; this however is more time consuming.

See the bottom of this page for Keypad Essentials anytime during this process!

0. Download Blender:

http://www.blender.org/download/get-blender/

1. Import into blender

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I suggest using renderdetail at level 2 for the first blender attempt, so that the point cloud is not super dense with vertices

[file] [import] [ply] …

the ".." means "back" in blenders file search

once imported, (may take ~10 seconds), zoom out to view your object (won't be centered). [Zoom using the mouse scroll]

Drag the object into the center of the screen

To rotate the object, hold alt/option key and drag your mouse.

2. Object mode vs. Edit mode

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If your object looks like a silver "skin," then you are in object mode.

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by pressing "tab" the object enters edit mode. (make sure you select the object first). In edit mode, you should see your mesh made up of the original point cloud.

Within edit mode, YELLOW dots mean they are selected dots, blue dots are not selected.

Press ["a"] to deselect all (["a"] also selects all when nothing is selected)

note: you can select the object by right clicking it (mac users place two fingers on pad and click)

3. Smoothing

After all vertices are selected (all dots are yellow), you most likely will want to "smooth" the object. This will help to remove some of the fuzziness of the object.

Select all vertices (all dots are yellow), and then press ["w"] and find "smooth"

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You will probably want to do this several times until your object looks much smoother (enter object mode by pressing "tab" to see the results):
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Note: you want to try to smooth enough so the object is not super fuzzy, but not so much so that you are flattening out every detail of the object! I usually smooth the object 5-10 times

4. Selecting desired vertices to edit, move or remove:

Enter edit mode, and de-select all vertices (press "tab" so that all dots are blue).
Press ["b"] once to box select, and ["b" "b"] (b twice) to circular select.

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the goal here is to select any part that you either want to move or delete. examples:
-you will want to delete excess noise or other parts that you either do not want printed or cannot be printed (say crazy hair in the middle of nowhere)
-you will want to move a part of the scan that for some reason was not positioned in the correct place (in this example, the ears were too far from their correct position, so i had to move them back here)

NOTE: often, you may end up also selecting vertices that are actually BEHIND the points that you want to select. If so, rotate the object and de-select those vertices.

You can de-select vertices by holding "alt/option" and then repeating the selecting process.

5. Removing excess vertices:

Depending on your "noise" levels, you may have a lot of extra mesh that you want to get rid of.

Enter edit mode and select all vertices you want removed (step 4)

Here I am removing the entire neck of the head scan because i do not wish to include that part in my print:
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Press ["x"] and select "delete vertices" to delete the selected vertices:
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Your object should now have those vertices remoived
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Repeat this for all of the excess vertices until you have only what you want to print. Also note that it may be easier to view what you are deleting by constantly switching back and forth between edit and object mode ["tab"]

TRY not to create any excess holes through this process by deleting vertices that are within the "good" part of the mesh.

6. Moving vertices:

Often, some points of the object will be in an incorrect position that you would like to push or pull back to its original position.

Here I have an ear that is too far back from its correct position:
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Select the vertices that you would like to move:
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Drag the vertices over with your mouse:
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This may cause random points to be randomly out of place:
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"Smooth" these points as well! they should go back to place, if not then move them back as well:
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7. Close Holes:

Note: if there are many holes, it may be easier to export your cloud into meshlab which has a "close all holes" feature.

Find a hole within your mesh and zoom into it. Select all vertices that are surrounding the hole using ["b" "b"]:
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Press the "alt/option" key as well as the ["m"] key and select "Merge - Center."
-if the shortcut does not work, try selecting "mesh" "vertices" "merge"
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Your hole should be closed!:
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8. Extrude:

Enter edit mode again, and select all vertices ["a"]. They should all be yellow.
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press ["e"] and select extrude "region"
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Extrude in desired axis. You usually want to extrude straight back (which is usually the z direction) so press ["z"] to guide the extrusion:
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Extrude enough so that the closest point of the extruded end is further than the furthest point of the original skin. (In my case, the extruded nose should be further back from the original ear)

By going back to object mode "tab," you should now have a 3D object that is simply a stretched out version of your original mesh.
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9. Make a flat back:

Instead of having one side of the object as an inverted mesh, you can make that entire edge/side flat.

Enter object mode, press "spacebar" [add plane]
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Scale plane ["s"] so that the plane is large enough to cover the side you want flat

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Move the plane back far enough so that it is behind all of the features that you want to print. You may have to rotate the plane so that it is perpendicular to the features of the object
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Once the plane is in the position that you want a flat back, click "object" "boolean operation" and then "boolean union"

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This operation may take anywhere from 5 seconds to 5 minutes! The time this process takes depends on the number of vertices within the objects (if you used noisethreshold level 0 and rendertail level 1, this process will take a very long time)

Finally, once the process completes, you should see something like this:
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If the mesh looks spotted, it means there are actually several meshes combined together.

Simply drag the already selected mesh over like so:
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Now delete the original mesh ["x"] "delete vertices" and original plane, leaving only the flat edge object:
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The only object left should either look like this:

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or this

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The difference being that the first has the plane sticking out from either side, whereas the second is good for a print.

If your object has a flat back to it, continue on to step 10. If there is a plane sticking out from the object, follow these next few instructions first:

From here, enter edit mode "tab"
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Select the four corners, (press ["b" "b"] to select)
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Press "alt/option" and ["m"] simultaneously, and then select "merge center"
-if the shortcut does not work, try selecting "mesh" "vertices" "merge"
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Your object should now look something like this:
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Now, once you return to object mode "tab" it should look as follows with a flat back:
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10. Make a printable bottom-side:

If you are going to print your mesh on a makerbot, you are going to need one side to be flat. Pick a side that you do not mind chopping off a section of. (when editing a face, i usually chop off the bottom of the chin or the top of the head)

Note: Depending on what the object is, it may be desirable to use the flat back as the bottom side as well.

The process of making a printable bottom-side is the exact same as step 9. Follow steps 9 to go from here:
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to here:
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Polyreducing + other notes

When you export your mesh, you want enough detail to capture every change in feature and shape; however, too many points will not only be harder to deal with, but will also cause blender to have far slower processes (or non-functioning ones)

1mb .ply files or less usually work great. (Threephase can export files up to 20mb)

If you have a large file, and you see Blender working slowly, you can "plyreduce the mesh" which rids of some excess vertices.

in edit mode, select all ["a"]
go to [object] [script] [polyreduce]
(polyreduce should recude all points, whereas polyreduce selection should only reduce selected ones.)

similar to smoothing, you can do this as much as you want - but it will decrease the resolution each time.

Keypad essentials:

It seems like a lot, but very soon all of these will be memorized

Rotate view: hold down alt/option and move your mouse.

Zoom: scroll mouse

Select Object: right click object (on mac, hold two fingers on pad and click)

Select all: "a" key

Select points:
-in edit mode, pressing "b" once allows you to box select points. Pressing "b b" (b twice), allows you to circle select [change size of circle by zooming in/out.
-to select one point, right click the vertices.

Select multiple points/objects: select first object/point [right-click], and then hold ["shift"] and select the next object [right-click].

Delete: "x" key
-usually you will want to delete vertices here (the yellow dots will be deleted)

Extrude: "e" key (must be in edit mode). once pressed, you can extrude in any certain dimension by additionally pressing x,y,z. Most likely you will want to extrude in the z direction

add mesh: "spacebar" will allow you to add an object (sphere, plane, cube..)

Move Object:
-hold down "left-click" and then drag the mouse a little across the screen. When you let go, the object should follow the mouse.
-to move in only one axis direction (say z..) do as above, and then press the "z" key. OR, simply drag the x,y,z axis on the object.

Rotate Object: Sometimes this is tricky, but all you have to do is draw a small arc around the origin, and it should start rotating the selected object.

Pan vertically: hold "shift" and scroll mouse [zoom]
Pan horizontally: For Windows: alt/option and scroll mouse
Do not know how to for Mac

Scale: press "s" key and then move the mouse around to scale.

view/alter dimensions: pressing "n" will pop up a window that shows you the xyz dimensions. Here you can alter each dimension (either individually or linked, by locking some)

color: press the "v" key, to enable/disable color. must be in object mode for this

Unless otherwise stated, the content of this page is licensed under GNU Free Documentation License.