Blender with Corona Renderer

Dear Everyone,

in this little article I want to show something I just recently re-discorvered for myself: The beautiful Blender (tush)!
You know it: the free, open-source 3d program with the very -ahem- own UI and controls. The underrated and negleted one. The one for the hobbyists.
Well – when I tried to get deeper into it this time on the outlook for a true alternative good addition to our current pipeline I realized (again) all of the things above are not necessarily true.

But let me start from the beginning:

rendering with blender and corona A7

Why?

I love simple and easy to use programs. I love ambitious projects.  Well, I also find it very good to look over the rim of a tea cup and learn new things.

Also I find it very important to know more 3d software packages  than the one you usually use – it frees up the mind to see how things could also be achieved differently – apart from the way you already know.

I tried Blender several times – but I always shied away from it again for several reasons: The UI is very special and it lacked a convincing render engine.

This changed. Since some time there is the Cycles engine – and exporters for Corona and Vray.

The exporter for Corona has been around for quite some time and I tried it once in Alpha7 days, before the corona 1.0 release. It worked quite good already, but it wasn’t developed further unfortunaltey. Until recently – August 2016 to be correct.

 

If you are really interested,  check the bitbucket repository to read the developement history of it (also the place where to get the corona bridge :) )

So, in the adventurous mood I was in, I started blender again – watched several quick-start videos for beginners like this one and imported an old scene I made a couple of  years ago. I was so amazed!

The whole handling of Blender suddenly felt easy when I lost all the anxiety of not being as quick as I use to be in max, having incorporated all the shortcuts – after some hours it really got fluent. I tried some basic stuff like box modelling, watched a lot of videos by the BlenderGuru and Creative Shrimp and it really felt right!

first try ever with blender and cycles

I tried first to use Cycles and got quite far with it – it has great potential and what really makes it strong is that it works both with CPU and GPU. So if you have some strong video cards in your machine you can actually get quite some good rendering times.

Well – I re-cycled (pun intended) this older scene, and well – it worked out quite good. The only thing i really noticed is that is was really hard, if not impossible to get rid of the grain finally. I tried all the things that is recommended like clamping, portals etc. There might be reasons for this – and maybe i should have rendered a bit longer. Well see for yourself:

 

I liked it – but as said above, i had a very hard time to get out the grain.

So, the next thing to do for me was to try out how the corona integration into Blender works these days. And it is far deeper integrated as you might think when hearing the word “exporter” – you have full control of almost everything like you know it from the 3dsmax version! The materials and render settings are very familiar, everything works just fine. (more later in the HOW section)

 

 

What

Well to get on this little story I better first show the images I made then with Blender and Corona. Please be aware that there’s no postprocessing applied apart from some minor tonemapping and contrast tweaks within Corona VFB. So here you go:

renderings with blender and corona

 

So – I was euphoric! I did not expect this being possible with free (!) software.
These are great times, seriously. OK – I got curious even more and tried out how this particular scene also works when rendered in cycles. So i did that as well. Well – It worked out as well but to be honest i really got a bit anxious about the rendertimes – which are similar to corona but still carry some persistent grain. Also I found it quite hard to get the colours right.
Due to strange color mapping behaviour, tweaking the material preview and render output don’t have too many things in common… but that is a whole different story regarding the color space of Blender (I know there are respective add-ons but still it feels not easy to use).
I think that would be one of the main reasons i would choose Corona anytime. You have to do weird gamma and exposure stunts combined with extreme clamping to get to make Cycles behave good in terms of color-mapping. I know these are strong words – If anyone wants to dicuss this, drop me a line in the comments ;) .

But well, below you see my results I got with Cycles from the same scene. There are some differences in color, true – well that’s how it is :)
Also – these have some postprocessing applied. Basically some curves and vignette – I know this could have been done in Blender, but I could not get it right – the contrast and curves behaved a bit weird due to the awkward colour-mapping tweaks mentioned above – I made these in PS (cheating, I know, Krita would be the proper way.)

 

So here go the Blender-Cylces-Photoshop renders:


As you can see: Quite nice – but it has some persistent noise that might never go away (rendered 10000 samples, so that is quite some time).
But apart from that, I personally like that result as well.

So let’s get to the the next part:

How

Well, how to get started. I could write a lenghtly tutorial on how to get into Blender in combination with the Corona – but thanks to the large user base of Blender (really!) and big community support there is already a lot of information out there. So let me compile this for you how to get started:

  • Get Blender
  • Download the Corona Exporter along with a Standalone of Corona Renderer 1.6 (it is a daily built – the 1.5 Standalone does not work with that version) please be aware that in current version of the exporter 4.10 is an issue with instanced geometry – so if you download it NOW and notice that.. i will be fixed soon, I am sure :) (don’t let that discourage you)
  • Watch this absolute beginner Blender tutorial series until you find yourself fit enough to dive deeper (anyway a quick google search every now and then always helps if you get stuck)
  • Also these channels for outlooking of what great stuff could be done: BlenderGuru and Creative Shrimp
  • For starting Blender with Corona watch this video available on the Corona channel.
  • There is also a dedicated forum section on the Corona Forum for the Blender integration as well as a wiki on the official Corona Website – both worth visiting to get started and/or to learn more.
  • And most important: Read the tutorial series on chocofur.com on Blender and Corona. They are very useful and complete – especially when walking the arch-viz path.

Well – and some little tips from my side:

Don’t get afraid of the Blender UI and shortcuts. Let things happen. There is the option to let Blender behave like Max or Maya – it might be good for jump-start. But in the long run this is a dead-end road: When you get stuck it is far more easy to find help online when using the standard key layout of Blender. Also there are some very good techniques and concepts within the way how navigation works in Blender.

For help on the shortcuts i can recommend this cheat-sheet. Make it your desktop wallpaper – after 1 week you don’t need it anymore, I promisse ;)

 

Other great things

Well – one of the biggest question of course is: Ok, Corona. But will Blender also work with Vray ?

Answer: Yes, as mentioned above there is an exporter for Vray, but we did not look into that yet.

 

How about mass-instancing aka scattering?

Answer: Blender has a great particle system, that exports to Corona Standalone. Basically it exports the same way like corona scatter would – so there it is: your full grown mass-instancing tool!

These at last are some tests I made just today:

generic scattering test with blender particle system and corona

 

scattering grass in blender & corona using the native particle system exporting as corona scatter. pretty wicked, huh?

 

Of course: after this is an engine-thing you can render 360 stereoscopic spheres with it! So going VR is also no problem with the Blender+Corona combo.
Click here to check out the VR-Walkthrough :)

conclusion/final words

Well – what can I say. I am pretty excited how good Blender works these days and how fine the Corona Renderer is integrated in it – I hope you might get curious a bit to try it out for your self! You won’t regret it!
I know, there are limitations and you surely cannot compare the Blender with full-grown “professional” software like the big ones we all know, BUT:
It is a great tool and it has potential to become a true replacement in certain scenarios. Also most important thing:
The only way to improve it, is by using it!
Find the weak spots, point them out. In opposite to a commercial product i have the feeling poeple involved in the developing circles are more open to issues and don’t cover them up for marketing reasons. Always remember: we are talking production software here and no consumer product. As professionals we are obliged to help improving our tools.

Render on!
Lasse

Comments

Show comments
  • Rafael
    One thing who helped me to use Blender was when a discovered that you can change the default right click to use left click instead, also the pie-menus are amazing... :D
  • Andreu
    Very interesting showcase and proof of concept. May I ask you what did you use to make the VR-Walkthrough in browser? Thank you.
  • wardepot
    Very nice work. I wonder how Vray for Blender beside Corona? Chaosgroup is working on Vray for Blender for very long time, I can't wait for your Vray test for Blender...
  • Jonathan Groberg
    You should look at the cycles denoiser, it is relatively new but it's all the blender rage on twitter and there's a few YouTube videos
  • Piergi
    I don't know what version of Blender you used, but you probably will be happy to hear that there is now a built-in denoiser, getting rid of the grain quite efficiently. On the side of the colour management, since a few months Blender uses the 'filmic' option, that uses scene-referred images. Both of those are game-changer for me. Try it out ;-)
  • lasse.rode
    thanks guys for commenting, sorry for me taking ages to answer :D @Rafael: thanks for the tip @Andreu: thanks a lot, we use krpano for this kind of work. it is a very nifty and simple tool. works great! @wardepot: tbh, i tried it but could not get it running - don't know exactly why. but from what i have seen, it already workds great! vray is also very powerful also with latest features in 3.6 @Jonathan: yes, i will - i have also seen good results. the problem with denoising filters - also in vray and corona - is they work "kind of" similar like jpg averaging. which 'can' result in ugly artifacts. i try to avoid it. @piergi: 2.78c - yes i have heard about the denoiser. need to try it serioulsy :D the filmic.. hm well. maybe i am to simple minded but it somewhat feels very stumpy to me not having a full dynamic output and baking in all colour mapping already. the corona e.g. gives you full float 32 bit output which you can treat as you like afterwards.. but maybe i just would have to jump into it. i have used the cycles a lot since my test 3 months ago - so..
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