User feedback

[Jager]

Hi,

I've been doing archviz animations with vray/nuke for five years. Lately, I've been asked to do one with Corona renderer and I must say that it was globally a good experience. Yet I encountered some  issues I wanted to share with you, in case it could help you improve some aspects of your software.

First of all, Corona consumes way too much memory. We have 64GB on each computer here, and we reached there limits (wich never happened to me before with VRay, I rarely needed more than 24GB). I guess Corona proxies ain't helping as much as they should. This is the biggest problem we've met. Render times were fair enough ((3H/frame, for 200 passes in HD), regarding that we choosed the double pathtracing solution. UHDCache wasn't available at that time and we were experiencing a LOT of flickering with HD Cache. I'm not sure Vray would have performed better with double brute force... We had enough CPU power not to worry about it anyways. However  memory is a big concern. It slowed down the entire production dramatically. Lots of computer freezes, crashes, etc.

Displacement was the second huge problem we had. I heard it has been improved in a recent release, so I can't truly talk about it's actual performances, but it was unimaginable, at that time, to use it. Yet it is one of the fundamental tools for producing believable images. Having an optimized tool for making qualitative displacements is one of my top criteria when I have to choose my renderer for a production.

Finally I had a few minor problems with render elements. I didn't find a lot of help on that particular topic here, so maybe I am using them the wrong way. In that case I'd appreciate your input on these subjects :

Why does the Zdepth reverses when you choose not to clip it...? It goes from white to black, and then white again... Is there any good reason for that? I'd also like to be able to reverse my Zdepth pass. Not a vital option, just a confortable one. And what about the possibility of having different Zdepth ranges into R, V and B channels?

The CShading_Shadows is strictly unusable. There's always a lot of fireflies in it.

I could use a velocity pass, as well as matte shadows, refl/refract glossiness, as they are called in VRay.

Is it already possible to have volumetrics appears in the render elements while being desactivated in the beauty ?

Thank you for reading, I hope that my user feedback will be helpful.

Jeremy

[juang3d]

The thing you say about memory, I agree it has to be improved, but in a recent project I did I was able to reduce the memory a lot using proxys, I'm not sure about this, but where you copying the proxys or instancing them?
In other render engines this has direct impact on how the proxys are internally handled, in Corona I'm not sure about this.

And for the other things, I think it's better if Ondra or someone with more knowledge in the matter answers you here :)

Cheers.

[cecofuli]

I agree with you, Jager. Corona eats more RAM than VRay. Maybe because VRay is a bucket renderer and Corona is progressive.
But, I talked with Ondra and he know this problem.

[Ondra]

for now it seems a lot of the RAM is consumed by embree. Unfortunately its "low memory" option is currently not working.

[Juraj]

Interesting about the Embree. I had huge issue when I tried to use Embree with early 3.0 Vray release, but subsequently it became usable after SP1 (or earlier patch ?) where they changed how it supported instances.

I only see the memory difference (Vray vs Corona) in instance heavy scenes (trees&grass), but very little in my regular scenes.