Tutorial - Half Wire, Half Solid, Smooth Transition

We can see everywhere these nice renderings of 3D objects, with a smooth transition from the original Mesh rendered in WireFrame, merging gradually with the final, Textured and Lit masterpiece.

This kind of display is quite easy to achieve, provided you already have the 3D Model :) Let's start with this model of a Hat. You can get the hat from : http://www.quality3dmodels.com/

Using your favorite 3D Software, position the Hat as you like, and do a normal rendering :

Solid Rendered Hat

Save the picture using a format that supports transparency, such as PNG.

Now, go to your 3D Software rendering option panel, and force the rendering to Wireframe. For 3DS Max, this would look like this :

Render Parameters for WireFrame

Resulting in the following picture :

Wireframe rendered Hat

Again, save the picture using a format that supports transparency.

Load both images in any decent 2D painting software. In our case, I used Paint.Net which is free and supports layers. You will need 3 layers, in the following stack order :

  • 3 : Wire View
  • 2 : Solid View
  • 1 : Background
Background Layer + Solid Layer + Wire Layer = All Layers

The result is pretty much what we want, but it doesn't look good enough. We need to use a gradient fade on both our Wire and Solid views to achieve the final result. In Paint.Net, the is the configuration you want :

Paint.NET Gradient Transparency

Now, Apply the gradient on Layers 2 and 3 to achieve the following effect :

Background Layer + Solid Layer Faded + Wire Layer Faded + Resulting Image

And you're done ! While looking around on the Net, I found another tutorial to achieve this effect directly in the 3D Software package : http://www.quality3dmodels.com/Tutorials/3dsmax/wiresolid/wiresolid.html. This trick may be effective for simple objects, but if you do not want to mess with your textures, you should use the post-processing method described here.