Press a texture into the surface

Before you start

You need a plate with a model on it, as in Your first print, and the model has to carry a texture. STL carries none, so it can’t be used. OBJ and 3MF can, and Encrust reads the texture when it opens the file, not later.

Do this step first on the part. Pressing replaces the model’s mesh, so supports and a hollow cavity you had already made are dropped with it (Hollowing and drain holes, Supports). Cut and split don’t carry the texture through either, so press before them (Cut and split). A saved .encrust project doesn’t keep the texture, so a model reopened from one can’t be pressed.

Check the file carries a texture

An OBJ needs its material file (.mtl) beside it, and that file has to name the image with map_Kd. Keep the image in the same folder: if the material names a path from the machine that made the file, Encrust looks for the bare file name beside the model instead. A 3MF carries its images inside the package. Encrust reads PNG, JPEG, BMP and TGA. A .dds image is refused.

A model may use several images, one per material: a statue with bronze, marble and brick parts presses each part from its own image. If one of several images can’t be read, Encrust refuses the whole model rather than press the rest.

Open the Relief tool

1. Press 6, or choose Relief on the tool rail on the right edge of the window.
2. Under “On the plate”, look for “Texture” (or “2 textures”, and so on) with the image’s file name. If it reads “No texture on the plate”, the file carried none, or the texture has already been pressed in.

With the tool open, the model is drawn with its images washed over it as heights: white is proud, black stays flat. This shows where the texture lands before you press anything. A hollowed model is drawn plain.

Set the depth

Depth is in millimetres, from -2 to 2, and starts at 0.5. It is measured on the plate, at the size the model will print: Encrust applies the model’s current scale before pressing, so 0.3 mm is 0.3 mm whatever unit the file was drawn in. A negative Depth sinks the texture in instead of raising it. Scaling the model after pressing scales the relief with it.

Encrust reads the image as greyscale, so mid-grey gives half the Depth: the height runs from none at black to the full Depth at white.

The depth is a starting point for your printer and resin, not a tested value. Your printer’s and resin maker’s instructions come first, and this guide says nothing about how well a given depth prints.

Set the precision

Precision runs from 0 to 1 and starts at 0.5. It sets the lattice the relief is cut on, and the panel prints it under the fields, as “The relief is cut on a 0.17 mm lattice” at the defaults on a small model. Precision alone gives 0.8 mm at 0 and 0.05 mm at 1 (0.2 mm at 0.5), but the lattice is also capped at a third of the Depth. At the default Depth of 0.5 mm that cap, 0.17 mm, is the tighter one, so a shallower relief is cut finer. It also means that at that Depth, Precision below about 0.57 changes nothing. A very large model gets a coarser lattice, because the cost of the field grows with its surface area.

Detail smaller than one lattice step is lost, whatever the image’s resolution. The whole model is remeshed at that step, not only the textured faces, so fine detail elsewhere on the part can soften too. Raise Precision if it matters. A finer lattice costs time and memory. If the budget forces a coarser one, the status bar says so after the run.

Press

Click Press. The panel reads “Pressing…” and a bar runs until the job finishes. The status bar then reads “Pressed 0.50 mm of relief into 1 model(s)”.

The press covers every visible model on the plate that carries a texture. The model comes back as new triangles, many more than before: a 12-triangle box pressed at 0.6 mm comes out at about fifteen thousand. Ctrl+Z (Cmd+Z on macOS) takes it back.

Then place the model and add supports as usual. The texture is geometry now, so it moves and scales with the model.

When the texture covers only part of the model

A map may cover some faces and not others. Faces with no texture coordinates don’t move at all. At the edge between a textured face and a bare one the surface steps, because the displacement jumps there. A statue where the flame or a base carries no image will show that step.

Files that were mapped by a flat projection can step the same way where the projection jumps, such as over the edge of a cube.

If something goes wrong

Press is greyed out and the panel says no texture

The file carried no usable image. Check that an OBJ’s .mtl sits beside it and names an image in a format Encrust reads, or that a 3MF holds one. A model that already had its texture pressed in carries none any more.

The relief looks blunt

Check the lattice in the panel: detail finer than it can’t appear. Raise Precision. If the status bar says a model “came out on a coarser lattice than precision asked for”, the model was too large for the memory budget at that precision. The relief is also blunt when the image itself is flat or low in contrast.

A deep relief folds or tears

Depth works as a displacement of the surface, which holds while the depth is small against the shape underneath. A relief as deep as a feature is wide folds. Lower Depth, or press and undo until the surface looks right.