Okay so I'm having a big problem in cinema 4D. I just opened it today and I dunno what I did to cause this but this happened and it's when anything is imported. I've got a really good graphics card and really powerful PC but I have no idea what's going on. Link below to what I'm on about. Gyazo is a safe website. Just google the name. It's just easier than uploading the file.
it looks like you set the Display settings to Lines. In the Display settings on any viewport window. It's easy to do accidentally since the short cut is 'N' followed by 'G' You want to be back in Gourad Shading probably.