Architectural Exterior Renders using Corona

[timkirkhope]

Hey Peeps,
So we all know Corona is friggin' awesome for doing closed spaces ie interior renders etc. So what's the general thoughts about using it for exterior renders.  I am about to start on a big project and was thinking about using Corona.  If admin is serious about world domination this should be quite an important topic.  Has anyone pioneered it for exteriors?  Will I get as good or if not better result than vray or iray?  Or is it just not built for exteriors??

Any feedback would be much appreciated as I don't want to jeopardise this success of my next project...

:) :) :)

[Captain Obvious]

It works better for exteriors, because exteriors tend to produce significantly less noise. The only thing I'm concerned about is that Corona's ability to handle high complexities really isn't what it should be. It uses a lot of memory and can take a long time to initialize on heavy scenes. It doesn't seem like Corona uses any memory cycling features (offloading stuff to disk and reloading as needed, or unloading and regenerating displacement polygons) to allow for really high complexities. If I had a project where I knew I needed to render large* amounts of raw geometry, I probably wouldn't pick Corona for the job. Anything less than about 20 million raw polygons, it's probably not worth worrying about.


* "large" meaning many tens of millions of unique polygons

[rambambulli]

I think corona is really excellent for exteriors. I'm a render amateur and used Maxwell because of the look and feel of the light. With Maxwell it was really easy to get a nice result. (For me. Nothing like some of the beautiful images on this forum :)).
With Maxwell the rendering times were the main problem. For me the problem with vray is the gazillion possibilities. I think Corona combines the best of both of them!

I attached my very first test with Corona. No post production only some cropping. I used a Revit model so it has very little detail and no interiors yet. (Revit? We are working/testing on a workflow from Revit. That's why.). I added some simple trees and grass.  Again I am a amateur and if you don't like the result it is certainly not because of corona!

@Captain Obvious. I agree. The scene I uploaded used approx. 14gb of memory (with a nice result after 10min.). I tried it on a 8gb machine and it took 25 min only to parse the scene. The original rendered image was 2400x1800 pixels btw.

[Ludvik Koutny]

There's no problem with exteriors at all. Exterior is not synonym for polygon heavy scene. That's what instancing is after all. I rendered all of my complex exterior scenes with 16GB of RAM without any problems, and these days, 32GB is becoming mainstream.

If you reach the limit in any other engine, you can still render your scene, it will just become terribly slow. Chances are you will not meet the deadline. So if you get over your RAM limit, you are already doing something wrong.

There may be some heavy duty VFX shots, which may require some trickery or advanced solutions to be renderable. But if we talk about regular archviz exterior cases, Corona should not fail you.

[timkirkhope]

Thanks for your feedback, you have convinced me to use Corona, my scene is a 10 story residential tower populated with interiors but the environment is all photograph so I can keep polys to a reasonable amount.
I assume the RAM requirement is for all render slaves or just the main pc?

Nice work rambambulli, how have you done the foreground?

[rambambulli]

Thanks timkirkhope! I did it with Forest Pack. Because this was a test scene I just used a FP grass preset and added a little bit of high grasses of my own (the parc is a bit swampie).
I also modified the Forest Pack standard materials to Corona materials.  I love the the way Corona's translucency works.
I haven't done this with the (Laubwerk) trees in the back. That's why they lack variation and they look plastic.

@rawalance. Of course 32gb is mainstream. I rendered the images on a 32gb machine. But the scene was so fast that I wanted to test it on an older machine.
CPU-wise the scene was still fast (even with some really old dual cores!) but for this scene the memory was the problem. Not Corona.

[Juraj]

Of course 32gb is mainstream

CGI Hipsters :- D no really, this lifted my mood.

Well, as others said, no qualm between Corona and exteriors.

I would just add that, there are still considerations one should take into account. Basically, any scene that will render under XYZ, should render just fine here, but, if you're coming from rather well developed, tweaked biased engine,
you might be doing things that more strict renderer like Corona (or any other path tracer) is not so forgiving. Where previously, you could interpolate some detail into mush, or adaptivity would solve it, mistakes here could lead into stuck noise,
but it really isn't fault of the renderer, it's the fault of user in such cases more often than not. (i,e. 1000 unnecessary lights, hidden/obstructed by complicated geo, caustic glass where not needed,etc..)

[Utroll]

for a feedback I've rendered 1.290M polys on laptop, mostly instanced (of course) on i7 laptop with 12Gb ram without problem, or let's say the time, but that was still 6hrs for 8000px large image. Ext archviz bird view. A6.

[timkirkhope]

Seemed to work well - Might keep using it, thanks for your help :)

[mbaloch]

Dear How do you retain hdri or sky background in final your final renders as I lost it all the time in my .exr files.

[philippelamoureux]

Exterior is easier to setup but if there is vegetation then I think I prefer interiors hehe!

[Rhodesy]

Its funny you should bring this up as historically I have always thought that unbiased style renderers like maxwell back in the day produced better interiors than the likes of vray but the reverse was true for exteriors. I think it has something to do with the clarity of render. Interiors are often clean lines and sharp which lends itself to the clean style of unbiased rendering i.e. no splotches. Where as exteriors benefit from a bit of dirt and irregularity so the splotches and artifacts from the biased rendering actually help here and the biased render looked too clean and less realistic. Things are a bit different now with AO / dirt shaders and rounded edges but I still think it holds a bit true. I still think if you lined up the best 10 coronal arch viz renders most of them would be interiors.

[micmac]

I assume the RAM requirement is for all render slaves or just the main pc?

Good question!

[snakebox]

There's no problem with exteriors at all. Exterior is not synonym for polygon heavy scene. That's what instancing is after all. I rendered all of my complex exterior scenes with 16GB of RAM without any problems, and these days, 32GB is becoming mainstream.

If you reach the limit in any other engine, you can still render your scene, it will just become terribly slow. Chances are you will not meet the deadline. So if you get over your RAM limit, you are already doing something wrong.

There may be some heavy duty VFX shots, which may require some trickery or advanced solutions to be renderable. But if we talk about regular archviz exterior cases, Corona should not fail you.

what resolution were you rendering in though? I find that once you get higher than 3000px, specially the 4-5K size Corona get exponentially memory hungry to the point where with 32gb ram you hit a wall and everything takes 10x as long.