Computer Aided Design

CAD Computer Aided Design is using a computer to create what we visualise to exist and it’s the cornerstone of how we design and build things. The history behind it is pretty interesting Alphonse Louis Poitevin discovers a process using sunlight and a substance found in gum that allows original architectural drawings to be reproduced. I can’t imagine how that happened! The process creates a negative copy where black lines turn white and blank space turn blue leaving the users with a blueprint allowing designs to be replicated and disturbed and allowing everyone to work from the same design. This triggered the 2nd industrial revolution.

The History behind Computer Aided Design is very inspiring in how we are using our computers to design things now and how with the help of A.I and IOT we are able to get different and unlimited opinions regarding design for a part or building a better sustainable future. Thank you chewing gums for inspiring Alphonse Louis Poitevin?

This week I will be using differnet open-source software to render a 2D / 3D design.

Inkscape

Inkscape is a free and open-source vector graphics editor and has all the tools needed to create a vector image and is very user friendly. I would like to draw and animate the Reuleaux triangle since I got attracted to it’s aesthetics and design.

1. To create the Reuleaux triangle first I started by clicking on create stars and polygons icon and setting the corners to 3. “Hold the control button to keep everything even”.

2. Create circle tool and create a circle from one angle of the triangle extending to the opposite side. Hold the shift and control buttons together while drawing: shift to start from a specific point and control to keep the ratio of the circle. We need to create three circles.

3. Move the first triangle and now we can see the Reuleaux triangle shaped in the middle, by clicking fill boundaries icon choose color and click on the triangle to fill it.

4. Go to file Export PNG Image and resize the page size to which desired or to Save As… to save the file in other file formats.

GIMP

GIMP is a raster open-source software. I would like to use GIMP to resize high resolution photographs and to test the possibilities and limitations for image compression and quality. This photograph is a good example for its range of shadows and highlight diversity.

1. I divide the width or height to how much I want my image to be scaled to Image - Scale Image... to enter the numbers.

2. Images were exported as JPEG by raising the quality from 0 to 100. File - Export As..

Results:

Freecad

Freecad is also an open-source parametric CAD software download and install the latest version from the website. I would like to repeat the process of the same design on Freecad and export the file and an objet oriented file and render it on other softwares.

1. Start by creating a new file and selecting the Part Design tab on workbenches, create a new body and make it active icon and then create a new sketch.

2. Select the XY Plane and click ok.

3. Click create a regular polygon icon and select triangle shape from the drop menu by clicking on the arrow and to set the constraint arc of the circle click on the fix the Diameter of a circle or an arc icon I set the diameter to 30mm and the triangle is now constraint.

4. We need to draw the three circles “click on the create a circle in the sketcher button” and drag the circle from one point of the triangle to the other and everything now is constraint.

5. Using Trim an edge with respect to the picked position tool, trim rest of the lines to get the result then click on “finish editing active sketch button” to exit sketcher.

6. Back on Part Design workbench click on pad a selected sketch and choose length.

7. Go to file then Export… the file as obj.

Blender

After drawing on Freecad I was able to export the design as .obj file and open it on Blender. It wasn't my first time to use Blender for generating 3D objects but it was my first time to render an animated object, I used keys to make the object rotate in 360 degrees and changed the lighting and the material of the object. Blender is a great and powerful open sourse software with lots of tutorials online.

1. Import obj. file and scale the object by pressing “S” button,
2. Click on the camera view icon to view the object via the camera.
3. Go to dimension properties and set the Frame Rate to 30 fps.

4. Set the timeframe of the animation I’m going for 3 seconds.

5. Click on the record button to set keyframes through the timeline.

6. Select the object you want to rotate and press “I” button on the keyboard and select rotation keyframe.

7. To export the object we need to set the correct file format and resolution to render, I will export the render of the animation to a png sequence.

8. After doing the setting go to Render and click on Render Animation files will saved at selected folder.

9. Open folder in terminal and run magick -delay 3 -loop 0 1.png*.png animation.gif

Result:

Conclusion

Going through different design software showed me how to imagine my final project on the computer. The softwares I used were all open-source softwares and very powerful, what impressed me most was blender and Freecad. What I really liked about using these softwares that I can export the design on one and open it on the other, I find that it is a great tool to play with your design and try different approaches and ways to modify your idea.

Design Files

Name	Type
Reuleaux Triangle Blender	.obj
Reuleaux Triangle Inkscape	.svg
Reuleaux Triangle Freecad	.FCStd

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