Rendering Wireframes in CINEMA 4D: Two Techniques That Get the Job Done
So you want to create a wireframe render for your 3D model in CINEMA 4D? Well, wouldn't it be easy if you could do it with the click of a button? Luckily for you, it's just about that easy in CINEMA 4D! Let's go over a few different methods you can use for rendering out a wireframe for your model so you can make your demo reel even better! Or just to add a nice touch to your render, because who doesn't like a wireframe overlay?
This first method is definitely the easier of the two and provides you with some really great results. It literally takes just a few minutes to setup and uses a cel rendering method, so let's go over how to setup a wireframe render using Cel outlines.
The first thing you'll want to do is change up your scene slightly, if you've already set up a beauty pass render then you'll want to make sure you don't have any backgrounds set up, you want just the model visible. This will make it make easier to composite everything together in a program like Photoshop.
Now open up your render settings. So go to Render>Edit Render Settings. This will bring up the render settings option box.
For this you can really set this up using any render engine in CINEMA 4D but for now let's just go with the standard renderer.
Now select the Effects tab and choose the Cel Renderer.
You'll need to adjust some of the settings here, so first check the edges option box, as well as the outline. If you were to have just the outline box checked then the line would only be rendered around the edges of the model. With the edges box checked as well it will create an outline along all the edges of the mesh. You can set the edge color to whatever you like; in this situation it will stay black.
Before you render though go to your Save options within the Render Settings and make sure the Alpha channel is checked and the format is set to something like a PNG. This will make it so that the background is completely transparent, so you'll have just the wireframe of the model.
Now select Render to Picture Viewer. There you go! You now have a nice looking wireframe render for your model. From here you can bring it into any external photo editing application and composite onto the beauty pass render. Wasn't that easy?
Now, while this method is as simple as turning on an effect it actually doesn't provide you with as much flexibility. If you noticed, the background of the wireframe is transparent, but what about all the white color in the middle of the wireframe? Since this is not transparent it means you have to set the blend mode to something like Multiply or Overlay in Photoshop in order to have the model and the wireframe show up.
You can actually get around that by using a different method, so let's go over how to set that up.
Sketch and Toon
This next method uses another Effect just like the first one, but it takes a bit more time to setup. The added benefit of spending more time is that the area within the wireframe will actually be completely transparent, giving you the best results.
Just like before, if you have any type of lighting or background setup for your scene you'll want to hide them while setting up the wireframe.
The first thing you'll need to do is go into your render settings by going to Render>Edit Render Settings.
Now go to Effect and choose Sketch and Toon.
With the new Sketch and Toon effect created go under the Lines options and set the line type to Edges, and deselect Creases, Folds, and Border. You'll also want to set the Hidden Cull to Project, and make sure the Self-Culling box is checked.
When you run a quick render you should see the same results as in the image. The wireframe is there, but it's not really looking correct, and since this is a toon effect the render has very cartoony shading, which depending on your project you probably don't want.
This is a pretty easy fix, so go back into your render settings and under the Shading options change the Object shading to Texture.
Now when you create a new render you'll see that the shading is a flat white color, just like the first method of using the Cel Renderer. This would work fine, but instead let's have the model be completely transparent and just show the wireframe.
To do this, first go back into your render settings and under the Shading options change the Background to Off. This will allow the background to be completely transparent as well.
If you run another render you should see the same results as the image. However, this is just halfway there. The background is transparent, but now you'll need to set the object as transparent as well.
So go into the Material Manager at the bottom of the CINEMA 4D UI. If it's not there, go to Window>Material Manager.
Select Create in the Material Manager and choose New Material.
In the new material attributes go to the basic properties and uncheck the Color and Specular box, and turn on Transparency. Now just drag this new material onto the 3D model.
Go back into the Render Settings and under the Sketch and Toon effect go to the Shading options and this time set the Object shading mode to Off.
If you do another render you should see just a completely black image, don't panic! Remember that the default wireframe color was black, so now that there is no background there is nothing visible.
To fix this just select the Sketch Mat material in the Material Browser.
Now go to the Color options and change the color from black to white, or any color that will show up in the render.
One important thing to remember is that in the Sketch Mat material you also have a lot of different options for the wireframe, like the thickness and opacity of the wire. In this instance the thickness of the wireframe line has been decreased quite a bit to 0.3.
When you render you should see the same results as the image, with a white wireframe and a completely transparent object and background.
Now go to the Save options in the Render Settings and make sure you have the Alpha Channel box checked.
The last thing you'll want to do is go to the Render options in the Sketch and Toon settings and change the line AA to Best. This will make sure that the wireframe resolution is high and there aren't any jagged pixels.
One last thing to note about this method is that you also have the option of displaying the entire wireframe. You may notice how that even though the inside of the wireframe is transparent it still renders as if there is an object still visible, so the other side of the wireframe doesn't become visible. That's because you set the Hidden Cull to Project and left Self Culling on. While this is probably something you want, you also have the option of displaying the backside of the wireframe as well, if you need to.
Go back to the Render Settings and under the Sketch and Toon effect go to the Lines option and under Hidden Cull uncheck Self-Culling.
Now when you render you should see that the entire wireframe is visible, including the backside of the mesh, giving you a much denser wireframe. While this is not something you'll always want, it's still great to have the option.
What's nice about this method is that you also have the ability to change the wireframe color to whatever you want inside an application like Photoshop.
Both of these methods for rendering wireframes in CINEMA 4D are quick to setup, and don't require any manipulating UVs which is always a good thing! While the first method can be accomplished in about one minute, the second method takes longer, but gives you more control. So determine which technique will work best for your project. If you have any questions share them in the comments below!