1st test with corona

[peterguthrie]

Hi everyone,

This is an old project of mine, and seeing as it is very simple I thought it would be a nice easy start for trying out corona. Each one got to about 200 samples i think or passes, or whatever its called ;) and took about 2 hrs.

Original set done with vray here: http://www.peterguthrie.net/archive/#/plainspace/

So... how do I get access to nightlies then!

Peter

[michaltimko]

I was waiting on your "first" post here hehe! As usual, very nice starters. Hope to see more images from you soon.
How do you feel working with corona comparing to Vray ? 

[Ludvik Koutny]

They look nice, but i think such a simple scenario should render a bit faster. Do you use PT+PT or PT+HD? As for the daily builds, once you reach 5 posts, you will see daily sub-section section in alpha builds section. There, you will just post a link to this thread, and you will get daily build key ;)

[peterguthrie]

I'm quite sure it can be faster, indeed I hope it can! I used PT + HD.

I've only had 1 day playing about with corona so far, so most settings still a bit of a mystery which is partly why I've asked Juraj to do a tips & tricks type post on my blog so that I and others can get up to speed.

will check out the alpha builds section, thanks!

[Juraj]

They look nice, but i think such a simple scenario should render a bit faster. Do you use PT+PT or PT+HD? As for the daily builds, once you reach 5 posts, you will see daily sub-section section in alpha builds section. There, you will just post a link to this thread, and you will get daily build key ;)

Why would you classify this as "simple scenario" ? Seems to be pretty lot of GI work. And I think all materials are specular, even the matte paint, as it does look so from last image.
It could be pretty high RGB value for white, though I can't know.

[Ludvik Koutny]

Yes, materials with too high albedo could cause some problems as well... or coronalights with directionality... Some of these vulnerabilities will hopefully get removed in future builds. The one with directional light is already gone, but there is no stable daily with that yet. As for albedo, it will always pay off performance-wise to keep diffuse and reflection ranges in reasonable boundaries. My top for diffuse is RGB 220, which i consider to be a white sheet of paper.

[michaltimko]

Regarding settings, there is no big magic behind imo. Playing with PT samples or with MSI/HD does the trick but, for the still images, changing those settings doesnt have drastical impact on speed/quality ratio.
For me, MSI parameter is most important for interior renderings.

Also, you can cover openings with planes with CoronaPortalMLT.

Here is my pretty simple test, how portals can speed up the rendering : http://forum.corona-renderer.com/index.php/topic,1551.msg11805.html#msg11805

[RolandB]

Here is Peter... waoooo, what some great artists here. I stay !

[peterguthrie]

Yeah probably every material has glossiness, and GI wise i dont think its the easiest scene to light.

Let me check if I had any directionality on the IES lights.. and what my white walls were set to.

re: portals, I thought I read somewhere that they werent always an advantage... ? I am using a HDRi sky.

happy to try one render with and one without to see if it speeds it up.

[Ludvik Koutny]

Yeah probably every material has glossiness, and GI wise i dont think its the easiest scene to light.

Let me check if I had any directionality on the IES lights.. and what my white walls were set to.

re: portals, I thought I read somewhere that they werent always an advantage... ? I am using a HDRi sky.

happy to try one render with and one without to see if it speeds it up.

In this particular case, portals will probably make difference as the skylight opening is not that big. They are very simple to use, just put a large quad over there to cap the opening and apply portalMTL on it :)

[michaltimko]

Portals should help with scenarios like you have here, where you need to "push all light thru that hole".
I have heard that they can slow down renderings in scenes with big openings, but i have never noticed any slowdown and im using portals almost in all my scenes.

[peterguthrie]

Yeah probably every material has glossiness, and GI wise i dont think its the easiest scene to light.

Let me check if I had any directionality on the IES lights.. and what my white walls were set to.

re: portals, I thought I read somewhere that they werent always an advantage... ? I am using a HDRi sky.

happy to try one render with and one without to see if it speeds it up.

In this particular case, portals will probably make difference as the skylight opening is not that big. They are very simple to use, just put a large quad over there to cap the opening and apply portalMTL on it :)

does the normal of the quad matter? ie. facing in or out?

[michaltimko]

does the normal of the quad matter? ie. facing in or out?

Keymaster (dev) told me that no, but im always face-in.

[Ludvik Koutny]

Yeah probably every material has glossiness, and GI wise i dont think its the easiest scene to light.

Let me check if I had any directionality on the IES lights.. and what my white walls were set to.

re: portals, I thought I read somewhere that they werent always an advantage... ? I am using a HDRi sky.

happy to try one render with and one without to see if it speeds it up.

In this particular case, portals will probably make difference as the skylight opening is not that big. They are very simple to use, just put a large quad over there to cap the opening and apply portalMTL on it :)

does the normal of the quad matter? ie. facing in or out?

It does not, but i adopted a habit of always having normals facing inside of an interior, in case functionality of portal changed somewhen in future. :)

[Ondra]

does the normal of the quad matter? ie. facing in or out?

No. Rules for portals currently are:
1) no double portals (2 layers of portals in the same window)
2) keep them as low-poly as possible

Restriction #2 was already removed in the unstable builds.