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Wow Oscar, You turned David's suggestion/question into reality in an hour!! Impressive. So how long will it take you to finish the Leprechaun??
I can't wait to see his boots! You've got a month till St. Patrick's Day...... 😉
Looks great btw.
 

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Discussion Starter · #7 ·
Folks,

I made an assumption everyone is knowledgeable on gray scale height map/depth map images for cnc patterns and I realized when I first started I had no clue about 99% of this stuff.

So for the new folks.

Gray scale height depth also referred to as depth maps are another way to create patterns for cnc machines.

Wikipedia: Depth Map. In 3D computer graphics and computer vision, a depth map is an image or image channel that contains information relating to the distance of the surfaces of scene objects from a viewpoint. The term is related to and may be analogous to depth buffer, Z-buffer, Z-buffering and Z-depth.[1] The "Z" in these latter terms relates to a convention that the central axis of view of a camera is in the direction of the camera's Z axis, and not to the absolute Z axis of a scene.

gcode ultimately is a series of x,y and z coordinate information used by the cnc software to control a router or other tool.

A depth map provides this information in the form of pixel information. Each pixel has an x and y position in reference to the image. Where it get interesting is the z information. It uses a gray scale to provide the height or depth of the z coordinate. Pure white is either 0/ground or pure black is 1/top of the pattern. Different software interpret this one way or the other (i.e. 0 can be ground or the top) so you may have to create a negative of the image so it carves correctly on your machine.

The images by themselves are not usable by the cnc machine directly. They have to be converted to a usable format and finally to gcode. Most commercial software has this function built in but there are several free options available as well. Do a web search for "image to gcode" for different examples.

Different authors use different colors when rendering or creating depth map images so don't think there is any big difference. They are converted to gray scale by the software in the end to get the black to white scale. Yellow version of the pattern below.

This is also why converting normal pictures to cnc patterns is so difficult. Regular pictures are not created with a uniform black to white scale for the height parameters. When the software converts regular pictures into gray scale the corresponding height information is not correct so what you get is noise.

Having said all that, depth maps have limitations. I only use them maybe 1% of the time for my own cnc carvings. The situation I have is my cnc uses a proprietary pattern format that is unusable by any of the normal machines so a quick and easy way for me to share patterns is through these depth map images.

Pros and Cons examples:

One benefit is size of files. For example I converted this pattern to a 25K STL file and it came out to 12 megs. This is a very simple pattern. For large complex patterns it is very easy to get files in the many hundreds of megs if not gigs size.

A con is they are approximations of true 3d geometry. Not all 3d models make good depth map images. Also, they can be difficult to make so they produce decent result.

Hopefully this helps someone starting in this adventure.
 

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Discussion Starter · #8 ·
Wow Oscar, You turned David's suggestion/question into reality in an hour!! Impressive. So how long will it take you to finish the Leprechaun??
I can't wait to see his boots! You've got a month till St. Patrick's Day...... 😉
Looks great btw.
lol. This pattern was a speed building exercise. The hat took about 5 minutes to make. Making a Leprechaun might take a bit little longer than that.

I think I might have a bridge troll somewhere. I wonder if they can be interchangeable...nope. lol
 

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Discussion Starter · #9 ·
Leprechaun's Face

So how long will it take you to finish the Leprechaun?? I can't wait to see his boots! You've got a month till St. Patrick's Day...... 😉
No boots but a quick face since I still need a lot of practice. Clothing for me takes forever. I am still not very good at them yet.

For anyone curious, I added a few timeline picks of how I sculpted this model. The last image is the depth map that can be carved.

The hat is from the previous model. The pipe is from a previous experiment where I was trying to cnc carve some smoking pipes. Total failure. :(
 

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