Voxel models

Cura now supports voxel models, by loading in a sequence of images if the first image ends in a number.

The XY are stretched so that the object fits inside while the XY ratio is maintained.
The Z of the images is independently stretched so that all images cover the whole 3D model.

I’ve used it to create some prints which are based on DICOM files from CT-scans.

Note that the surface model is extracted from the DICOM files in a separate program (3D slicer).
I converted the DICOM files into standard png images using MATLAB.

Then I converted the images such that the highest density equaled the density I had set in Cura and a cropped them to where the surface model reached.

This is the result:

This is a sample MATLAB code:


files = dir('osseux/*.dcm');
for file = files'
path = strcat(file.folder, "/", file.name);
a = dicomread(path);
min_val = 300.0 / 32768.0 + .5;
max_val = 1800 / 32768.0 + .5;
minn = min(min(a));
maxx = max(max(a));
a_mapped = uint16(int32(a) + 32768);
adjusted = imadjust(a_mapped, [min_val max_val], [0.0 1.0], 1.2);
[filepath,name,ext] = fileparts(file.name);
outfile = strcat(file.folder, '/output/', name, ".png");
imwrite(65535 - adjusted, outfile{1});
end

Don’t blame me if this crappy hacked together code doesn’t work on your machine! 😉

Here’s a sample converted .cdm file:

Evaluation meeting

Today I had to present my Evaluation report, which covers the research topic, the progress and the planning (a.o.).

I got a provisional Go, which means that if I keep it up I can expect to continue my PhD research after the Go/NoGo meeting at 12 months into the research.

Variable Fuzzy Skin

I realized that after having implemented Fuzzy skin texture mapping I have never showed any examples using the method.

Perhaps this is an interesting line of research after all.

I’ve printed an example below to show the capabilities of the technology.
However, this is not really a good real world example.

This technique could be interesting for making the surface of a handle bar more rough to give it more grip, while keeping the rest of the object smooth.

Top of the can showing 3 different roughness levels:

Side showing the word ‘making’ in a more rough surface finish.

Side showing the word ‘in’ in a more rough surface finish.

Side showing the Cura logo in two different levels of roughness.

Making my chairs at home scratch-safe

I’ve been having trouble getting my chairs at home not to scratch my floor and after several failed attempts at solving the problem I have considered the solution which should have been obvious to me: 3D printing the anti-scratch thingies!

The final working design envelops the foot of the chair and plugs into the hole in the foot of the chair.

3D model file on YouMagine

By beautiful chair:

The bottom side of the leg:

The bottom side of the leg with the printed sock:

The top side of the leg with the printed sock:

Hatching journal paper

I’ve published a paper about gray scale printing in the journal Computers & Graphics
3D hatching: linear halftoning for dual extrusion fused deposition modeling.

The accepted manuscript can be found here: https://arxiv.org/pdf/1805.01375.pdf

The final paper can be found here: https://dl.acm.org/citation.cfm?doid=3083157.3083163

 

This is an extension of the conference paper called
3D hatching: linear halftoning for dual extrusion fused deposition modeling

https://dl.acm.org/citation.cfm?id=3083163

Texture Processing

Texture printing reveals to be a promising technique.

It requires a very good XY calibration, however.

Still need to calibrate the grayscale colors for it to be perfect….