Is there a line render engine for Blender?

Question

I am looking for a render engine capable of rendering vectors, i.e. vertices, edges, curves, etc -- objects that have no volume & no faces.

I'd also like the render engine to be free.

Below is an example what I am trying to accomplish. See how there are only points and lines in the image? That's the style I'm wanting to achieve.

I am also hoping the render engine can make much nicer pictures than this (higher resolution, control over materials, transparency, etc), and also to make animations.

Given these constraints, are there any vector render engines that stand out as good solutions?

Answer 1

Blender Internal

BI can render wireframes on edge only meshes, whether shaded or shadeless:

BI can also render halos, which work on vertex only meshes (there are a few in the middle of the above scene), but they are affected by distance.

OpenGL

However, you could try using the openGL preview render (using the same system that renders the viewport)

Unfortunately, options for coloring objects individually is rather limited using meshes without faces. You can tweak some things (e.g. vertex size) by editing the themes, but this is obviously not what it was designed for.

You can render animations and stills with openGL render by clicking the buttons in the header of the 3D view, or in the render menu in the Info panel (at the top of the window):

For example:

Original answer:

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Freestyle can render a scene as svg, using either SVGwriter or this set of python scripts.

Note that freestyle requires faces to work.

Answer 2

Adding a Minimal Bevel to a Curve

If you are only wanting outlines, such as this:

then you can achieve this very easily with either Blender Render or Cycles Render Engines by using a very minimal bevel on a wireframe curve object. Here is how you can do this:

1. Either create an object or import one.

2. If any parts of your model are curves, then convert them to mesh:
   Select the curve objects -> ALTC -> Convert to Mesh

3. Now delete all the faces from your mesh:

   • Select your mesh

   • Go into Edit mode (TAB)

   • Select All (A)

   • Delete faces only (X -> Faces Only)

   • Exit Edit mode (TAB)

   

4. Now select the remaining wireframe and convert it from a mesh object to a curve object:
   (ALTC -> Convert to Curve)

5. Add a Circle Curve (SHIFTA -> Curve -> Circle)

6. Select your wireframe and:

   • Add a bevel to it:
     Object Properties panel -> Curve tab -> Geometry section -> Set Bevel Object to the circle curve created in step 5

   • Scale down the circle curve until your wireframe is as thin as you want it to be:
     Select circle -> S + Drag mouse

   

7. Add a material to you model. If you like a flat look without any shadows, use an Emission Shader -- then you won't even have to worry about adding & adjusting lamps. To do this, select the model and then in the Object Properties window:
   Material tab -> Add new material -> Surface section -> Surface -> Emission

   

When rendered, it will look like a wireframe:

If you render and feel the wireframe lines look too thick, scale the circle curve down some more. However, if the circle is already so small you don't see it in the 3D Viewport, select it in the Outliner:

Answer 3

For completeness, its worth noting that there are systems to render vector data like this.

To name a few:

• asymptote
• MathGL
• pst-solides3d

Writing an exporter for programs like this shouldn't be so hard (depending on exactly what you want to display).