FAQ

This FAQ covers operational questions and assumes the use of versions up to 0.7.2. Details might not apply for later versions unless specifically noted. Some details might not apply to earlier version of the application. It does not address questions about purchasing, downloading or upgrading the software. For such questions, please see the Store FAQ

Q: Do I need an AMS/MMU to print HueForge designs?

A: NO! Though an AMS/MMU makes printing easier, the application is specifically designed to have only one color per layer, so ANY printer capable of pausing for a filament swap can reproduce a HueForge print.

If you are using an AMS/MMU, you might find the information below about using more than four colors useful.

Q: What is TD and why do I care?

A: TD is short for transmission distance and is a measure of how much light penetrates a filament. It is used to calculate the amount of color blending that occurs between layers of filament so the application can predict resulting colors properly.

Q: Can I use my own filament that’s not listed in the filament library?

A: Yes, of course. However, all filament needs to be properly characterized by its RGB number (hex) and its transmission distance (TD). HueForge uses this to provide an accurate prediction of the resulting print. Filament data can be added to the library as Owned by clicking New Filament and saving to the library for future reference. Note: Clicking the checkbox next to a filament that is in the Unowned library moves it to the Owned library (press Save Library for future use).

Q: How do I get the TD value for a filament?

A: HueForge has a large library of filaments, from various companies (like BambuLabs, Esun, Fillamentum, Overture, IIID Max, Numakers, Paramount 3D, Polymaker, Protopasta, Sunlu and others). Additional filaments and makers are being added as they become available.

However, if yours is not already in the library, there are several ways to determine the TD of a filament. These include printing a small two-color sample, searching social media sites for published community supported filament databases or directly measuring it using the recently released sensor, the TD-1, from Ajax-3D.

Printing a two-color sample using a filament with a known TD (generally black or white) under the one being tested is a common way to get the TD value of a filament. Various samples have been proposed and used recently; however, it is now suggested to use the Seashell_Test.hfp found in the HueForge/Tools folder to determine the TD of the filament. "The Seashell Method.PDF" file in the folder describes how to use this technique. If you are in the Discord HueForge group (invite comes with purchase) go to we-share-seashells for pictures of seashells users have printed to gauge the TD.

Some examples of community filament databases: At Reddit [1], Google Drive [2], TBD

The TD-1 is a sensor device designed and provided through Ajax-3D that integrates directly with HueForge to read the TD of a filament inserted into it and to estimate its RGB value. More information is available at his website: [3]

Q: What filaments do I want/need to do HueForge prints?

A: To start it is good to have a black and TWO whites, one with a medium TD (around 4 or 5) and one with a TD less than 2. Then for good gray-scale images a light and a darker gray are useful, though on a budget one gray can give good results.

When planning color projects, it is most useful to have reds, blues, greens, yellows and maybe a brown as well. Remember that color blending is the name of the game with HueForge, so it is not absolutely necessary to have all of the colors and shades present in an image to get some stunning results.

However, as skill is gained it might be necessary to consider having two different versions of very similar colors, one with a low TD and one with a reasonably high TD. In particular, this is most true for white, where three levels of TD might be considered: one low, one mid-range and one high. The mid-range works for most images, where the low TD can be used as the last layer or two to get some “pop” in the whites where appropriate. The high TD white is often useful in muting a color or changing its tone, like shading in an otherwise blue sky.

Without a doubt, one disadvantage of owning (and using) HueForge is that you WILL want more colors of filament than you ever imagined you would.

Q: Why Can't I Save My Filament Library?

A: Since HueForge is not an installer, you must have directory permissions to write into the Filament directory. C:\Program Files and C:\Program Files (x86) are protected directories and Windows will not allow writing into them. Documents or simply C:\HueForge or C:\Programs\HueForge will work.

Q: What do the sliders do?

A: The sliders (bottom left panel on the default screen) are the fundamental means of adding to and adjusting the colors (filaments) in a HueForge design.

Dragging a filament from the library panel (left side of the screen) and dropping it onto a slider makes it available for use in the design. Colors can be added to any unused slider or to replace a color on a previously used one. Note that right clicking on a slider opens a dialog menu that can also be used to add or modify a color and/or a filament.

Moving a slider up causes that color to be added to the design up to (but not including) the layer number shown immediately below the slider. The number of layers of that color is the difference of the layer shown and that of the next lower slider (which may or may not be to the left of the slider being moved).

Slider heights do not need to progress upward from left to right, though it can be helpful to have them ordered that way. The Reorder Sliders button is used to resort the sliders into that sequence.

Moving a slider to a zero-layer height removes it from placement in the model, but not from the slider. Another way to do this is to click the layer number box, which toggles that slider to remove that color from inclusion in the model or to restore it to use. This method leaves the layer height unchanged.

The number of layers of a particular filament is the difference of that filament’s layer height and the height of the next lower filament. That is, the slider numbers represent where filaments end, not the total number of layers used in a print.

Q: Does HueForge create the Gcode to send to the printer?

A: No, Hueforge saves the project in four files, generally to a folder named HueForge/Projects. These are the [Project_name].HFP file, a copy of the original image with the same name as the project, a [Project_name].STL file of the geometry model, and a [Project_name]_describe.txt file with the information about the filaments and layer change information to be used in your favorite slicer.

Q: I’ve had success with a grayscale print, but as soon as I try to add color everything goes south. What am I doing wrong and how can I fix it?

A: Adding colors to a HueForge image isn’t always straightforward. One way to learn how to manage colors is to use the examples provided in the HueForge/Projects folder. Load them and examine the sliders and other settings to see how the results were achieved. Then nudge sliders and other controls to see their effects. Then try loading one of your images that has similar colors in place of the original and see how it looks. This is especially true for modes like Color Pop (see #Q: When do I need to use Color Pop and how does it work? for additional information) and Color Aware (see #Q: When do I need to use Color Aware and how does it work? for additional information).

Additional information on how to use Color Pop and Color Aware is available here. There are also several video tutorials by HueForge [4] and others available on YouTube [5].

Q: How do I select filaments/colors to match my image?

A: Right clicking on a point in the source image in HueForge opens a dialog menu with two choices; Find Closest Filament or Create New Filament. Selecting the first-choice sorts both Owned and Unowned filament libraries to place the filaments in nearest color order. If an Owned filament color is not acceptable a filament near the top of the Unowned list can be tested to see if it provides a better match.

Unowned filament items can be tested in the design to see how they perform without any obligation to purchase them. If you want to find a source of that filament right-clicking on color swatches that have a triangle cutout on the lower right will open a dialog with a Buy Filament option that takes you to an affiliated sales portal of that filament’s provider.

Q: I'm new to HueForge and I think I've done everything correctly. But in the slicer there is only black?

A: HueForge output contains the description of which filaments/colors were selected and what layers those colors occupy. However, it does NOT build a 3mf slicer file, because they are not fully standardized between slicer applications at this time. Rather, it is your job to define the filaments and the layers (height) at which a swap is required. This information is available in the [Project_Name]_describe.txt file that is created when the project (Project_Name) is saved.

Q: How do I make my print thicker so it’s not so floppy?

A: The easiest way to do this is to increase the values of both the Min and Max depths in HueForge by an equal amount. Then to speed printing, the layer heights of the part of the print up to the Min depth can be increased to reduce the number of layers. This is called a Height Range Modifier in some slicers (not variable height). If it is used, the color changes are added at the layer height in millimeters, rather than the layer number.

Q: I'm trying to do a print with a transparent background, but there is a rectangle where it should be blank in the slicer. How do I fix this?

A: That is the Common_Terms Lazy Programmer Rectangle (LPR). It is a set of zero height triangles that disappears when sliced.

Q: Can I turn the print over to make it completely flat?

A: No, because HueForge designs have only one color per layer. It often uses more than one layer of the same color, but a flat print would need more than one color per layer to produce the image. However, since the prints are generally thin, in most applications the surface texture is generally not a problem, even for things like coasters. And in other applications, like faux materials, the added texture gives an added sense of realism to the end product.

Q: Will it hurt anything for me to scale up/down the model (STL) file in the slicer?

A: Scaling the model up or down in HueForge is the best approach. However, if you just need to do a small adjustment (say 10-15%), it can be done in the slicer for the X and Y dimensions, only. Do NOT scale the Z axis as it changes layer heights, which adversely affects the color blending.

Q: Do I need a purge tower with HueForge prints?

a: In a word, NO. Because a HueForge print intentionally blends filament colors to create the image, a little overlap of the previous color will be unrecognizable in the final print. Save the time and filament by turning off the purge tower.

Q: How do I print with more than four colors when I only have one AMS?

A: You can swap filaments during the print in your single AMS, though you have to be sure not to miss the swap. So, either add pauses, or pull the fourth color that is going to print after the print is started (once the printer starts doing ANYTHING after the model is loaded). Add the extra filaments in the slicer. When you start the print and it asks you where to map the filaments, you select the correct slots (say fifth color in slot 1, sixth in slot 2, etc.).

Note: Pulling the fourth color is probably preferred, because if you ARE there to reload it, putting the color back in means the print will not pause at all.

Q: When do I need to use Color Pop and how does it work?

A: Pictures with one region of color over a monochrome background benefit from the Color Pop mode. This mode stacks two color spectra one on top of the other. This puts the background of the image on the bottom of the print and the colored part above the background.

The original version of HueForge required breaking the image into separate images that were then joined after printing to accomplish this. This newer mode merges the process into one workflow within HueForge. Think of it as stacking two HueForged designs on top of each other. To do this it is necessary to define each region from dark to light, most often by duplicating the black and white filaments, once in the lower grayscale region and the second set to define the boundaries of the upper colored region.

An online help with a detailed explanation for Color Pop mode is available here.

Q: When do I need to use Color Aware and how does it work?

A: As with Color Pop, Color Aware is sometimes the best way to get the needed color separation that a project demands. This is often the case when the image contains two or three dominant colors but few greyscale areas. Like Color Pop, Color Aware reproduces the color spectrum multiple times one on top of the other.

The difference is that instead of separating grayscale from color, Color Aware separates levels by the primary RGB colors: red, blue and green. Control is provided to expand or contract the color levels based on a particular project’s needs.

An online help with a detailed explanation for Color Aware mode is available here.

Q: Can HueForge be used to make lithophanes? If so, how is it done?

A: Yes, before its release Hueforge started out as a tool to help produce colored lithophanes. Selecting Lighting Settings > Blending Type > Lithophanes enters that operational mode. Monochrome lithophanes with cool colors (blues or greens) OR warm colors (reds/yellows) are easily developed, but full spectrum images need special treatment discussed in some detail in the article How to Make a Stained Glass HueForge Lithophane.

Q: Why when I port my HueForge into my slicer and add the filament swaps, it seems to not work with color?

A: The view in the slicer certainly looks different from the HueForge window, because the slicer doesn't know how to blend colors. Clicking on "Slicer View" in HueForge will reveal more or less what the slicer will show.

Q: If a filament painting requires more than four colors do I have to have multiple AMS/MMU?

A: Not at all. The BambuLab AMS allows you to 'hot swap' spools while printing. If you have a five colour print, you can take out the first spool in the AMS once it has completed printing and replace it with the fifth spool. As long as you have told the slicer that the first spool and the fifth spool occupy the same slot in the AMS, you will be perfectly fine!

Q: Why is my Export STL Option Grayed Out?

A: You have loaded an STL file as your input (most often the TD_Step_Test.stl). As such, there is no STL output to export, you already have it. HueForge does not modify pre-existing STL files.

Q: Why when I have a transparent image there is still a rectangle in the slicer?

A: Two options here - first, make sure your image is ACTUALLY transparent. If you don't see the checkboard behind the image itself, it isn't transparent. Second, if it really is transparent, then it's the result of the "Lazy Programmer Rectangle". That is, a zero-height region that disappears when sliced.

Q: Why do I have different number of layers between the HueForge program and the slicer?

A: The most common reason this happens, especially if the layer is off by one or two layers (HueForge says you should have 10 but the slicer says you have 9 layers) is because the image has tall spikes of colours that appear unprintable in the slicer. Portions of the image that are generally thinner than your line width will be ignored by the slicer and therefore will have one or two fewer layers than what HueForge expects due to these spikes. This video helps explain this occurrence: HELP! Why Doesn't my Mesh Height Match!?