Tag Archives: Python

Family Build Up

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One of the most common questions I, and possibly any other digital artist gets when they present their work is how they do it. I occasionally reveal some of my methods in my tutorials but otherwise I like to show screenshots taken at various stages. I came across this build up script a few months back and have now finally got it to work! Here’s my previous family portrait being reconstructed:

This script isn’t a true reflection of how I drew it but gives a good idea about the amount of detail I go into with my work. The reason I didn’t finish it is that I had already had the script running for ten hours and it was only half finished! Luckily there’s options to resume, but at this rate I’ll be doing it until February!

I think I may do this a lot more with my work.

Blending Inkscape and Blender

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One of the things I’ve always wanted to do is to work on an image in a 3D environment but then export the resultant image to an svg. Being the open source nut that I am my main weapons of choice are Blender for 3D work and Inkscape for vector. These programs have their advantages and their disadvantages. The main advantage they have over many similar programs is that they’re open source and free. They’re very capable products and are used quite widely and are being actively developed. In fact, Inkscape is getting ready to release version 0.47 (I’ve used a prerelease and it’s awesome)

For my task of exporting 3D models to SVG Blender falls slightly short because it doesn’t natively support this. There are a few plugins that have attempted to offer this and do well, but sometimes crash or give unexpected output. That, and for some users going through the hassle of finding the plugin might be too much.

The disadvantage Inkscape has is it’s handling of lots of nodes. The moment you hit around 10,000 nodes the program begins to noticeably slow down. For most simple logo work this isn’t a problem, but when you come to illustration and highly detailed artwork it gets in the way. This was the main thing stopping me from using the SVG that can be generated from Blender. To test it yourself, import an SVG into Blender and then export it as an SVG using either Pantograph or VRM. You’ll notice that it is now made up of about several hundred smaller shapes.

Before Import to Blender: 11 Objects, 124 nodes

Before Import to Blender: 11 Objects, 124 nodes

inkscapeblendertext

After Blender import: 2264 objects with 6792 nodes

This makes colouring or modifying the shape really hard. Sometimes, in Inkscape you can just highlight all of the shapes, go to Path > Union (Ctrl + Shift + +) to combine them all but sometimes it makes it all disappear.

Luckily there is a technique to get this to work. If you import an SVG be sure to apply the Ninja Decimate modifier to the shape and drag the Ratio slider down (thanks to heathenx for this tip). Please note that this only work if you shape is a mesh, so hit Alt + C and convert your shape to a mesh.

If you’re working with text you may notice that after you’ve applied the Decimate modifier and dragged the slider down all of your text looks… crap.

screenshot_15_01:24:52

This is because the modifier is treating the text as a whole shape and thus reducing the face count of the whole combine shape rather than treating each character as an individual shape. You need to separate them. To do this, in Edit mode (hit TAB to get there) hit P (don’t do this in normal mode. It runs the Blender game engine and will most likely crash Blender).

Separate menu

Separate menu

From the Separate menu choose All Loose Parts and now each character is an individual shape. Now, if you run the Decimate modifier on each individual character you have a lot more control over its final appearance.

After Modifications: 324 objects, 972 nodes

After Modifications: 324 objects, 972 nodes

I exported the text to an SVG using VRM but you can do so using that script, Pantograph or the 3D Polyhedron extension in the Render extension menu in Inkscape. Here’s another render showing exactly why you might want to go through this procedure:

70 objects, 36601 nodes

70 objects, 36601 nodes

After basic modification (text from an upcoming project)

After basic modification, 4042 nodes (text from an upcoming project)

The Decimate modifier has its limits. Where a human would simply combine two big triangular faces into a rectangle the modifier sometimes misses this and just over-complicates things and sometimes completely destroys a shape. This is where I ask the Blender community for assistance. Is there a script to easily reduce the face count of an object?

I think native SVG export is something that Blender should work towards in the future. There’s just too many possibilities and opportunities!

Blender renders

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For the past month or two I’ve been getting my head around Blender to do some 3D modelling. It’s a tough program to learn, but with the aid of some very useful tutorials and strong community support I feel I’m getting somewhere!

As well as using Inkscape to make vectors I want to explore the possibilities of using Blender to render 3D models as vectors. There’s so many benefits of this approach as long as it works. To do this I’ve tried out to vector rendering scripts written in the python programming language, VRM and Pantograph. VRM was easy to install – just dropped the file in the scripts folder – but Pantograph was a bit more problematic. If you’re going to install it make sure you have the right Python libraries installed! Here’s the original Blender output:

Original file rendered in Blender

Original file rendered in Blender

I’m getting some reflection off of my surface, but I’ll work on that another time.

Here’s the results of rendering a simple 3D snake model in Pantograph:

Pantograph render of a snake

Pantograph render of a snake

The Pantograph render produced the smoothest results by far. When taking it into Inkscape the final drawing is separated into several groups. For the snake you had a group for the outline, the silhouette and the wireframe. Depending on the complexity of your model you may want to delete the mesh. The only problem I’ve encountered is separating objects. Pantograph likes to merge to objects together, thus limiting editing capability. Still, you could always do most of the editing in Blender itself

Render from VRM

Render from VRM

This render using VRM reminds me a lot of the old Playstation/Sega Saturn graphics. You could subdivide all of the faces to get it smoother (set smooth has no effect on it), but it’d take forever to render and you’d end up with an unnecessarily large vector (.svg) file. Still, using VRM is useful for relatively simple objects. You could even combine the two renders!