3D ART creation software and methods

[lasersafe1]

My recent experiments in 3D engraving have led me down the path of looking at image heightmaps, bump maps, etc.
These maps can be created in a number of ways.
1. By 3D laser scanning a real 3D carving.
2. By the purchase of some pretty expensive 3D carving software.
3. Through manual photo manipulation in PhotoShop, Gimp, etc.
4. By methods not intended for the purpose.
5. By smart individuals that might write their own software and (hopefully) make it open source.

What is the heightmap? For our laser requirements it is typically an 8 bit grayscale image. Our lasers will burn deepest for black and shallow for white. Everything in between is a different burn depth. The image is also sometimes called a bump map, but the term bumpmap is more often used for a very small file that is repeated over and over behind a material when using rendering software.

Here is a simple example.
This lizard shape provides depth control information to the controller. The darker the color, the deeper it will burn.
It wouldn't matter what shade of grey you put this on top of. The laser will burn this lizard based on these shades of gray. In this first example, the lizard image is sitting on a pure black background, so the entire background is cut away.

In this next example, the lizard image is sitting on top of a white background, so the engraver is going to skip the white and only burn the lizard down into the wood.

That would be kind of ugly, so the trick is to try to blend the surroundings with a linear shading that brings the image back to the surface. In the next set of images we can see how this is handled by the professionals.

Notice how the outline of the image fades from the black "deep" cut to the white front surface in a linear shading of gray. Below we see the result in wood.

So the main purpose of this thread is to brainstorm about ways to create these files. I have played with ArtCAM Pro, which is a very expensive software package for CNC machines. Some people who are using Mach3 for their laser will indeed still need something like this, but those of us that simply need the grayscale height map to put into the engrave controller could get away with much less.

When I think of 3D artwork done in software, the first program that comes to mind is Blender.
1. It's Open Source
2. It readily accepts scripts to perform various tasks.
3. It already knows how to handle heightmaps, but it will be a learning experience to figure it out.
4. It has carving tools built in and plenty of artists that love to show you how to do things.

(don't ask)

http://wiki.blender.org/index.php/Doc:Tutorials/Textures/Maps/Creating_a_Heightmap_from_a_Plane

http://www.blender.org/features-gallery/gallery/art-gallery/

Now this might have been done by laser scan, or it may have been sculpted. I don't know. Here is the link to the creator: http://blenderartists.org/forum/showthread.php?p=1630877

The point is that if the software can represent this and it can export a heightmap, then we only need to put it all together and all learn how to use Blender.

Any other thoughts or ideas out there?

[timogiles]

lasersafe1,

I've playing around with STLs a little bit lately, but I was approaching 3D engraving from the point of view of slicing and STL into a bunch of layers. The free version of netfabb will slice an STL for you, but it outputs to a bunch of useless (to me anyways) file formats. One of them though is called .SSL and it is an ascii file that can be parsed out into a bunch of closed forms at each of the sliced layers. I was working on a python script that will parse the .SSL into bitmaps for each layer (which I have working), but I could probably just as easily make one bitmap and combine all the layers to make a grayscale image like that. I'll give it a shot and let you know how it goes.

BTW, this is my first post on the forum. I've been lurking for a few months and reading all that is going on around here. I have a small CNC that I use to cut PCBs on with a dremel tool. I a couple of weeks ago I picked up a 1 watt 808nm laser diode off ebay. I have it attached to my CNC and I've been playing around burning foam and marking wood. I thought it was a good baby step into all this high power laser business.

[timogiles]

Now that i re-read your post: are you looking for a good program to make 3D models, or a way to convert 3D models to height maps?

[lasersafe1]

Correct. Making a quality 3D model is the hardest part of this whole process. Simply taking a 2D image off the web or something you have made in photoshop is easy, but when you move to 3D, you need a height map. GantryCo.com sells these images for $125 a piece, and yes they have some real artists that create them. I think that they actually sculpt and then 3D laser scan them. Perhaps it is all done in computer, I don't know.

I am not much of an artist, and I don't have an engraving business to justify the cost of purchasing these images. Still, I know that there is a large volume of shared 3D imagery in the Blender community. Suppose I wanted to make a border for a picture frame that has nice round grapes on a vine with realistic grape leaves. I could find a shared image, set a plane at the midpoint of the object, and then export it in a 256 level gray height map.

[lasersafe1]

BTW, this is my first post on the forum. I've been lurking for a few months and reading all that is going on around here. I have a small CNC that I use to cut PCBs on with a dremel tool. I a couple of weeks ago I picked up a 1 watt 808nm laser diode off ebay. I have it attached to my CNC and I've been playing around burning foam and marking wood. I thought it was a good baby step into all this high power laser business.

Welcome to the forum. 808nm is a baby step, but not a good baby step. You have purchased one of the most dangerous wavelengths available because high power 808 appears as a dim red light and can fool your eyes into thinking it isn't high power. Be very careful, because even the dim reflection off your workpiece is hazardous to your retina.

[lasersafe1]

Just bumping the thread here. Anybody thinking about 3D? I still think Blender would be the way to go.

[LeonS]

Hi LS1,

I have been doing some experimenting with ways of doing smooth gradients with a minimal amount of scans. For instance 5 raster scans at progressively higher power produces a smooth 32 value ramp. But that is off subject.

There is a large body of people hacking the Microsoft Kinect. It has a low resolution IR camera and projector that can provide 3 dimensional representations of its surroundings colored however you want; including black is "far" and lighter is "nearer". There has been some interesting work on using the point clouds provided by the Kinect. These works can be of value for creating 3D meshes and images that are useful for laser engraving.

On the Thingiverse site TBuser (http://www.thingiverse.com/tbuser/things) has been doing some cool work using point clouds generated from photographs. The heavy lifting is done for free by a web site (http://www.my3dscanner.com/index.php). After you get the mesh you can import into Blender and then generate your depth map image. This is something I am going to pursue after I get my laser finished (real soon now!) I am going to make a 3D printer next so I'll be able to use the techniques and programs for two purposes.

- Leon

[lasersafe1]

I would like to drop in a 2D drawing and then simply pull selected areas forward and push others back with smoothing tools. Working with a laser, we can't go to extremes, but it can indeed give a 3D look to the finished product. I played with Delcam ArtCam, but it is a severely limited pirate copy that doesn't let me save anything and it crashes all the time. (you get what you pay for .. or don't pay for). I know that Blender could be used to do this same exact process for free, but have never sat down to work out the details. I was hoping someone with more time and knowledge of Blender would write up a tutorial.

[BenJackson]

I would like to drop in a 2D drawing and then simply pull selected areas forward and push others back with smoothing tools.

Vectric Aspire's "2.5D" inspired design tools do pretty much exactly that: http://www.youtube.com/watch?v=V7UbccVNPSs

I can imagine some convoluted paths to achieving this in free tools but nothing so automated as Aspire.

[lasersafe1]

I understand there are existing "very expensive" software packages available. Yet I don't think that a Blender solution is as convoluted as you may think. Most modern open source software packages allow you to build scripts to perform different functions. As a hobbiest I can't possibly consider the Vectrix option. Of course if you know of a site for cracked download, I would certainly like to experiment.