Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] General Discussion => Topic started by: easyease on 2017-04-11, 19:09:21

Title: Opacity channel sends render times through the roof
Post by: easyease on 2017-04-11, 19:09:21

Hey everyone,

I've been using Corona for a couple of weeks now and I'm really enjoying how well integrated into C4D this render engine is.

I've been trying to set-up a basic tree. It is a standard-issue tree rig, with a leaf material that contains an image in the diffuse and a black and white image in the opacity channel. However, once the black and white image is loaded in the opacity channel, render times shoot through the roof. Even a basic scene, with only a ground plane and a single tree is taking around 20-30 minutes on my machine. I've attached the basic scene below.

Am I setting this up wrong or is this kind of performance expected with an object like a tree that contains many leaves all with their own opacity channels? Thank you for any help you can send my way.

Title: Re: Opacity channel sends render times through the roof
Post by: TomG on 2017-04-11, 19:45:59

I was getting an estimated 4 mins on loading the scene. This came down to 1 minute if I used a Corona Bitmap shader in the Opacity rather than the PNG directly in there, and enabled "Clip" for the opacity. (either change on its own also makes a big difference, but combined made the biggest reduction in render time). Hope this helps!

   Tom

Title: Re: Opacity channel sends render times through the roof
Post by: Cinemike on 2017-04-11, 20:56:13

Quote from: TomG on 2017-04-11, 19:45:59

I was getting an estimated 4 mins on loading the scene. This came down to 1 minute if I used a Corona Bitmap shader in the Opacity rather than the PNG directly in there, and enabled "Clip" for the opacity. (either change on its own also makes a big difference, but combined made the biggest reduction in render time). Hope this helps!

   Tom

Now that's incredibly good to know!

Title: Re: Opacity channel sends render times through the roof
Post by: easyease on 2017-04-11, 21:13:51

Quote from: TomG on 2017-04-11, 19:45:59

I was getting an estimated 4 mins on loading the scene. This came down to 1 minute if I used a Corona Bitmap shader in the Opacity rather than the PNG directly in there, and enabled "Clip" for the opacity. (either change on its own also makes a big difference, but combined made the biggest reduction in render time). Hope this helps!

   Tom

I appreciate the help, Tom. Using the Corona Bitmap shader helped significantly. However, I don't see a "clip" box below the mix strength slider. I am running Corona A1.6.

Title: Re: Opacity channel sends render times through the roof
Post by: TomG on 2017-04-11, 21:30:37

I'd grab the latest daily build :)
https://forum.corona-renderer.com/index.php/board,40.0.html

Title: Re: Opacity channel sends render times through the roof
Post by: easyease on 2017-04-11, 21:44:44

Quote from: TomG on 2017-04-11, 21:30:37

I'd grab the latest daily build :)
https://forum.corona-renderer.com/index.php/board,40.0.html

Problem solved, thanks again!

Title: Re: Opacity channel sends render times through the roof
Post by: TomG on 2017-04-11, 22:07:11

Good to hear, and np! Always good to reduce render times :)