These days, it seems everything Peter Guthrie tells me to do, I do. I'm going to have to watch this before it gets me into trouble (on the other hand, Peter is definitely not the worst person to get directions from).
So, after he mentioned playing with Corona, it was only a matter of time before I had a go at it. But to be fair, I had been watching the forum for some time and was very intrigued by the great images by Juraj, Blackhaus and others. (Credits, too, to Peter and Lasse at Xoio for waxing lyrical about Corona over a recent lunch).
Here are a couple of images I put together using mainly old assets re-shaded from scratch (trying to understand how things work in the process). I had some minimalist post-pro done to them: curves, CA, glow and a photo filter in some cases. But nothing too drastic.
I also thought I'd jot down a few comments about the engine. Please bear in mind that I've only scratched the surface. In particular, these were rendered using PT/PT and leaving pretty much all the settings at default, with one exception, which was lowering the highlight compression from 1 to 0.5 (not sure what it does but it looked nicer). So it can be that my comments are factually wrong. If so, I'd appreciate it if the more experienced users could point out my mistakes.
WHAT I LIKE:
- Simplicity: The fact that great results can be had right out of the box is amazing. Whatever you do, don't make it more complicated.
- Speed: Corona is blazing fast on my Z820. Half of these images were rendered small at 1200x1200, the other ones at 2400x2400. I left most of them to render for a few hours but, really, the small ones were very usable after 30 minutes (comparable to Octane on one solid GPU). And these scenes are not simple HDR-lit product shots. They are all taken in a physically enclosed space, with lots of indirect lighting bouncing around. Some of the images are slightly noisier, but these are the ones I stopped after an hour. Given a bit more time, I'm sure they would have resolved completely, including the (very nice) bokehs and highlights.
- Light: I can't quite put my finger on it but I find the way light diffuses very subtle and pleasing.
- Great material preview with quality setting: Definitely a workflow improvement over most other engines.
- Beautiful glass and metal: Again, I'm not sure why that is, but I find convincing glass and metal are much easier to achieve than in other engines I use regularly. They also render a great deal faster.
- I love the fact that one can open, close and resize Max windows while rendering. A small point but it makes life nicer.
WHAT I'M MISSING:
- A physical camera: These were all shot through the V-Ray Physical cam, just because it's the one I tend to use all the time. I have no patience for the standard Max cam and its fantasy Mickey Mouse settings. Of course, none of the Physical cam's settings work, but I think the possibility to tweak F-Stops, shutter speed, ISO, etc. in the camera would be a cosmic improvement on the current workflow, which involves (at least as far as I can see) changing the intensity of the lights one by one to get the desired effect. Perhaps this is because I like to work like a photographer but this way of doing things is quite painful, I think. Let me know if I'm missing something here.
- DOF: I couldn't find a way of tweaking the depth of field in the camera. Corona seems to apply a "standard" DOF that has nothing to do with the F-Stop. I know there is an override in the render settings but touching those seems like a very inefficient way to work. Now there may be some settings for this in the standard Max cam but I couldn't find them.
- SSS: I couldn't find it, so assume there is no SSS material, although I haven't played too much with the translucency and absorption settings (not sure what the latter does, really). I render quite a lot of food, but things like Marble, candles, tree leaves will also never really work without SSS.
- I missed my favourite plugins a lot (Multitextures, MightyTiles, Railclone...) Getting these supported would make a huge difference for me and may actually be the thing that would tip the balance towards full-time Corona use. Conversely, it would be hard for me to use Corona as my primary engine without such support. Similarly, V-RayDirt and V-RayDistance are also things I use literally all the time, especially in big scenes where I don't want to unwrap all the geometry. Working without them would be a step backwards.
- Itoo's ForestPro and Railclone have a very memory-efficient way of distributing instances in Vray and Mental Ray, which, as per Itoo's website, is not available for other supported renderers, meaning no scene in these renders can every be as complex. For someone like me, who tends to work on big, not very optimised, scenes that fill all of my 32GB, this is definitely an advantage. I must admit I haven't tried Corona's scattering tools.
- A Blend material allowing the merging of more than two materials. I do think the Max Blend mat works wonders for Corona. It looks really, really good. But merging blends with blends if one needs more than two layers seems like an inefficient way of doing things.
- HDR sampling. I'm not sure I'm getting the same quality of shadow definition from big HDRs, which I get from V-Ray or Maxwell. Again, it's perhaps a bit of a subjective thing and maybe there's a setting I overlooked there.
- I love progressive rendering but in rare cases, it is actually nice to have buckets, for instance to check the final image output on a very small portion of the image. (Couldn't find how to do a region render in the Corona VFB but must admit I didn't look very hard).
If this sounds overly critical, then it conveys the wrong impression. I was generally extremely impressed and, with some of the above-mentioned issues fixed, could consider a full switch to Corona.
Having said all this, here are the images:
