It’s often useful to have both raster and vector data in the same job. For instance, if you want to create an engraved medallion with your logo on it, you’ll probably want to raster engrave the logo (or parts of the logo) and also vector cut out the shape of the medallion (i.e., the outside circle). RetinaEngrave3D requires you to be a little careful with colors when you want to do something like this.
Whenever you print an image from, say, CorelDraw to RetinaEngrave3D, all the features in your drawing will try to show up on both the raster screen and the vector screen (unless you’ve told RE3D to ignore raster data). Your task is to arrange for only the features you want rastered to show up on the raster screen, and only the features you want vectored to be vectored. The two screens behave differently.
The Raster Tab
On the raster screen, everything you see in the on-screen preview will be rastered. There’s only one control that can change what you see: the slider marked “B/W Threshold” in the “Raster Properties” box on the right side of the RE3D screen. When you’re working with a grayscale photograph, this slider is used to set the level of gray that will be treated as black. Everything lighter gray will be white, and everything darker gray will be black. If you set it to 255, the whole screen will be black; if you set it to 0, the whole screen will be white. If you set it somewhere in the middle, light colored features will be hidden and darker features will be visible. The secret here is that colors are treated as shades of gray, too. Yellow will be treated as a light gray, while darker colors like blue will be treated as darker shades of gray. Black, though, is always the darkest color. So what you need to do is make sure your raster data is true black, and your vector data is some other primary color(s). Then in RE3D, on the raster screen, simply adjust the B/W Threshold slider until all the vector data disappears, leaving just the raster data visible.
The Vector Tab
On the vector screen, you don’t get an actual preview. Instead, the color of each feature in your design is important. Each primary color you have used in your design is automatically assigned a line in the “Vector Layers” table. That includes black, which is what you used for your raster data. If you designed your raster data in a vector program like CorelDraw, chances are good that some parts of it will show up on the vector screen as well. Most likely, you’ll see an outline of your raster features, which you probably do not want. Since you drew them in black, they will all be controlled by the settings you put on black’s row of the Vector Layers table. If you set the “Passes” column for that row to 0, all black vectors will be ignored. They will still be visible on the screen, but they won’t be used when the job is run on the laser. Perfect!
Of course, for this to work, you have to make sure all the features you do want on the vector screen are a color other than black. Stick with the primary colors (red, green, blue, cyan, magenta, yellow) since that’s what RE3D is looking for. (Also, remember that you probably want these features drawn with zero stroke width, which CorelDraw calls “hairline”.) Again, each color automatically gets a row in the Vector Layers table. Set the order (if it matters), speed, power, and passes (usually 1) for each of these colors, according to what effect you want.
Raster then Vector
Once you have all this stuff set correctly, you can use the “Raster then Vector” mode (selected by a pull-down near the top of the window) to run both parts of your job. Note that switching to the Vector Cut tab in the main window resets this pull-down to Vector Mode, and likewise switching to the Raster Engrave tab resets it to Raster Mode. So finish your checking of both screens before selecting Raster then Vector mode. If you forget, you’ll get raster or vector but not both. As long as the material doesn’t move, you can recover by simply running the other mode manually.
Separate Raster and Vector Jobs
Sometimes it just isn’t convenient to use colors this way. For example, if your raster data isn’t pure black and white but also contains some grays or colors, you’ll want to adjust the B/W Threshold slider to get the best-looking treatment of those non-black colors. That may not be the same threshold setting you’d need to hide all the vector data. You could always go into a bitmap editing program like Photoshop (or Corel Photo-Paint, which we do have installed) and alter the raster data to be pure black and white, but that’s an extra hassle. Instead, you might find it easier to just handle the raster and vector parts of your job separately. You can put them into separate files, or from a single file you can temporarily delete the parts you don’t want, then print to RE3D, and then undelete them. Or, at least in CorelDraw, you can select the parts you do want, and in the Print dialog check the choice marked “Selection” in the “Print Range” box to print just those parts.
There’s a catch, though. If you print the raster and vector separately, they might not be lined up the way you want. Recall that when you print anything, RE3D finds the smallest rectangle that encloses everything you printed (the “bounding box”), and shoves that rectangle up into the upper left corner. If you print raster and vector data separately, each will have its own bounding box. If you’re not careful, they won’t be the same, and your raster and vector data won’t line up properly. There’s a standard trick to solve this problem: before you separate the raster and vector data, draw a yellow rectangle around the outside of your design (and don’t use yellow for anything else). Then include the yellow rectangle with both the raster data and the vector data. Yellow is a very light color, so your B/W Threshold setting will probably let it disappear. In the Vector Layers table, you can set Passes to 0 for yellow to eliminate it from the vector job. But in both cases, the yellow rectangle will be included in the bounding box, so everything will be lined up just the way you want.
(See also this Raster and Vector Rendering post, for a more visual explanation.)
