Rendering a wireframe is a very common task for 3D
artists and depending on your 3D application it can be extremely easy to do through various render settings. However, not all 3D programs allow you to render your model's wireframe with the click of a button. Now, it would be nice if you could, but programs like MODO
require a bit of a work around to create a decent-looking wireframe.
Of course, there's the option to export the model you created in MODO into an application like 3ds Max
to simply render the wireframe, but let's face it, not everyone has access to those programs, and if MODO is your only 3D app within the pipeline then you're going to have to make do with what you have.
Let's go through the simple technique you can use to create a nice wireframe render for your 3D model, whether it's for your demo reel or simply to spice up the look of your render with the always pleasing wireframe overlay.
Using the UVs From Your Model
This method while easy, does take a bit of work and an external 2D
program like Photoshop
or even Microsoft Paint, if you're on a budget! While this technique takes a bit of setup it still can be accomplished relatively quickly. Let's go through the process of using your model's UVs to create a wireframe overlay.
The first thing you should do is create a duplicate of your 3D model, this is important especially if you have a textured model, so you can render a beauty pass, and then the wireframe pass and composite it together in a program like Photoshop.
Now you need to create a new UV map for your model, this is especially important if you've already laid out the UVs and your model is textured because the unwrapped UVs will get destroyed. So select the UV viewport layout.
Now make sure you're under the Lists tab, with your entire model selected, and open the UV maps and select (new map) which will be grayed out.
You can name this new UV map whatever you like, and click OK.
Now within the UV window select UV Projection Tool.
You should see a new set of properties open up called Create UV, here you want to make sure you set your Projection type to Barycentric
Now just click inside the UV editor window and you should see something that resembles this image, a red square. Now depending on your topology you may get something that looks different, depending on if you have any triangles or n-gons on your model.
The next step is to go into a program like Photoshop, and create the image that will act as the wireframe on your model. So create a new file, with the dimensions 200 x 200 pixels.
Now double click the background and create a new layer out of it.
With the layer selected open the "fx" tab and select the Stroke effect.
In the Layer Style settings change the size to 4px and make sure you have the position set to inside. You should now see you have a simple white box with a black outline around the edges, which will act as the wireframe. Go ahead and save this image as something like a PNG or JPG. The size of the stroke will determine the thickness of the wireframe.
With MODO opened back up select the shading tab to view the Shader Tree.
Select the Assign Material button which opens up the material creation box, you can name it whatever you like, but make sure you set the specular to 0.0% and the Diffuse to 100%.
With the new material selected open the Add Layer drop down.
Now go to Image Map>(Load Image) within the Add Layer drop down menu and navigate to wherever you saved the image on your computer.
Your model should now resemble what you see here, with the wireframe image you created in Photoshop placed along the UV coordinates.
If you go to your Render viewport tab you can take see what the render looks like. You want to make sure you don't have a background setup, because you want to bring in just the car once you're ready to composite. When you're happy with the render, you can hide the model duplicate and show the original with the textures applied and create a beauty render and bring it into Photoshop and simply place the wireframe render over the beauty pass and set it to Multiply
Until there is a simple way to render wireframes in MODO like there is in other 3D applications this technique is likely you're best bet for getting a decent looking wireframe render that doesn't take a significant amount of time. If you want to learn more about MODO check out Introduction to MODO.
If you have any questions or comments be sure to leave them in the section below!