Slow Rendering on any model with Corona Rendering

[dikomilaz]

Hello, I am using Cinema 4D and I'm trying to use Corona Rendering.

Unfortunately, even the smallest models (currently trying to render a shoe) take hours and hours to complete. In fact, I haven't been able to complete a single render I've tried. I always switch to regular rendering after three hours. However, regular rendering makes the image less beautiful, of course.

I don't know if it's my computer's fault or if I'm using the wrong settings, but I'm tired of waiting for a single shoe to render.

Please, tell me what I must do.

- dikomilaz

[TomG]

The first question - did you set a Pass, Time or Noise level limit? If not, then Corona will render forever, even though the image is good enough to be considered done. By default, since Corona can't know how you want to control when an image is counted as complete, none of those limits are set and Corona will just keep on rendering.

If you mean that after hours of rendering, the image still has noise or does not look good, we'd need much more information - we'd need to see the image at least (submitting the scene is even better), and we'd need to know what render settings you were using, which version of Corona, which version of Max or C4D (and indeed which one ;) ), which OS, etc.

[dikomilaz]

Thank you for your response. No, I did not set a limit yet, because the model is never rendered completely.

For example, I am using Cinema 4D, the latest student version, and this is what the photo looks like when I render it in Cinema 4D settings:

https://ibb.co/fT67Y8

And when I use Corona Rendering, after three hours the image still looks like this:

https://ibb.co/dpvC0o

And as you can see, the centre of the shoe is still missing and there is no background whatsoever.

Anyway, I suppose I might be doing something wrong or maybe my computer simply can't handle the rendering.

[TomG]

Without a limit, the render will never stop. The look of the shoe and lack of background sounds more like a scene set-up issue - what is the background in the scene? The native C4D Background is not supported if I remember, and there are also some infinite ground style things that C4D does that are also not supported. The other question would be what the material is that is being used - it would be best to use a Corona material (but if it was a Corona material, it wouldn't render in the native C4D renderer - I am assuming when you say "render it in the Cinema 4D settings" you mean render it with one of the native C4D engines?)

If you did not set a limit, it will render forever. If using something that is not compatible with Corona (a material, background, or infinite plane), then for sure leaving it to render longer won't fix it. You should in fact be able to tell after 1 pass that something is wrong, the image will be noisy, but the missing background would tell you that something is not right. EDIT - that's one of the benefits of progressive rendering, the scene will always look like it is going to look like even after 1 pass, just that the noise will get less and less after each pass; anything missing or wrong in that first pass will always remain missing or wrong in later passes (just the noise in the image will get less); this means no waiting for buckets to render to get to a certain place in the image to suddenly see that something is broke :)