Hi GettingRusty,
Looking good! The main thing to keep in mind is that an image's pixels are interpreted as height values. An image with lighting on it is going to have raised parts where the light is mostly hitting the surface. For example, an image like this:
...results in a canvas like this:
...when you're probably hoping for something more like what originally created the lighting-rendered image, which would be something more like this:
The key is having proper height/depth data if you're using an image, or using a 3D model. Or, if you at least have a black-and-white image you can load it as a raster-layer and trace to a paths-layer and then use Shapes From Paths to generate a 3D shape. You can do the same directly from a 2D vector, like an SVG or DXF that's loaded as a paths-layer. In this instance, you'd want the actual 3D model of the dragonfly from which the image was rendered - that will allow you to generate toolpaths that actually conform to the shape and details of the model itself, effectively turning your carving itself into the 3D model that is naturally "rendered" by surrounding illumination sources. This is what a relief carving is supposed to be.
Having a photograph or lit rendering (like your dragonfly image) is good though if you want to make a halftone or lithopane, but to create a relief carving - a 3D carving of the thing - you'll want a proper heightmap and/or 2D form to generate toolpaths from, or trace to paths that you can then generate 3D shapes from for toolpathing off of.
( EDIT: I thought I'd also include what the actual heightmap for the above example looks like here, just so you can compare with the original image at the beginning of my comment that is only a 3D rendering of this heightmap )
I do think the wood is also of poorer quality than you would want for such a small detailed carving. Of all the woods I've cut so far I've found red oak to be the worst thus, not that I know what kind of wood you're cutting here but it definitely reminds me of red oak's stubbornness. It has really coarse fibers and ends up being very stringy on the edges of cuts. A harder wood like maple or oak is much better for small detailed projects and cuts.
For relief carvings, the best way to go, toolpath-wise, is to use a flat-end cutter with a 2.5D milling toolpath and a Leave Stock that prevents it from exactly approaching the canvas' form. Then come in with a ballnose cutter and a Parallel Carving toolpath with a very small stepover to remove everything else and clean it up. Here is an example project that uses the Rest-Machining option to restrict cuts to the relief carving itself, after removing a bunch of material around it: 5x7x0.5 Deer Relief.pnc Note how the 2D/2.5D milling operations have a smaller border so that more material is cleared, and then the re-roughing/finishing parallel carving operations that employ the rest-machining option are using a different Layer Group that has a larger border so that no vertical cuts are generated at the edges/walls/corners due to using a smaller cutter. We're working on a way to use a paths-layer as a boundary for clipping an operation's cutpaths to in lieu of using the rest-machining option the way that this project does to minimize total cut time.
As long as you have no immediate plunge cuts in your relief, and it gradually enters down into the material with each successive cutpath, you can usually get away with just having a single parallel carving operation and a small stepover that's shaving material with each cut, and as long as you have no vertical walls in the cut while you're using a tapered ballnose it will be fine. Here's an example project where the whole thing is done in one pass that cuts all the way down: 8x8 Tree Of Life 1-Pass.pnc
In a situation where it's unrealistic to do the thing in one pass, it's best to use a 2.5D operation with a larger flat endmill cutter to hog out most of the material, and then come in with your ballnose cutter(s) to go the full depth in one pass afterward.
We're working on getting v1.81b out ASAP right now, which is largely a bugfix update, but the next update we're aiming to include several new features - including some new toolpath types and capabilities! :]
- Charlie