One of the advantages of the MPCNC is that you can create some quite intricate work pieces. Relief carvings are 2.5 dimensional art works. They can be made from many of the height map pictures that are available on the Internet however, the holy grail of relief carving is to take a standard picture and create the height map then create the relief carving from that. It sounds simple but actually it’s not so easy. The height maps that are available online look almost like an X-ray and give great detail to the relative heights of the artwork. I created a piece from one of these pictures and it turned out to be an acceptable carving.
The picture that it came from looked like this
As you can see by the picture it has been modified to show the high points as lighter colors and the low points and darker colors and gradients in between describing the contours of the horse. I am not sure how these pictures are created, I imagine that someone with artistic skills modifies the picture to create the height map. Given that there are many of these pictures online there may be many practitioners in this artist creativity.
I tried to create something similar from a very straight forward picture of a Poppy.
I just took the picture into an image manipulation program (GIMP) and made it grey scale then inverted it the result was this.
As you can see the center of the Poppy would be standing proud (it’s the whitest part) the letters would stand up, the petals would be lower but the heights may not be what one would expect or desire from the picture.
I have been experimenting with this technique and found this video that explains a different technique that gives you a little more control over what is going to be high and low. However, I found that the directions in the video are great but you need to make the gradient black in the foreground and white in the background which is opposite to what is shown. Once you create a picture this way you can use that as your height map. I found that taking that picture into Inkscape and saving it as a plain SVG made a big difference in the time it takes Fusion 360 import the picture as a mesh.
In Fusion, I am using image2surface which is an add-in it takes the height map image and creates a mesh from it.
Once you have the mesh in Fusion you can create a new form then use the convert tool to convert a quad-mesh to a T-spline once this is complete you have your model that can be used in the model space. You can take the T-spline body and split a solid with it, that will give you a block with the relief on it.