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General => Terragen Discussion => Topic started by: freezurbern on July 23, 2014, 07:11:27 PM

Title: Multiple images, different shadows
Post by: freezurbern on July 23, 2014, 07:11:27 PM
Hello, I'm trying to make a skybox (six images on the interior of a box to show an entire world) for a video game, and have hit a snag. I've done these before but I have never had the issue below. When I render the camera views, the image with the sunlight in it has a darker shadow than the other images and causes a very visible line. Perhaps the image would explain better:
[attach=1]
I feel like Terragen 3 is doing something different in the sun image and I'm missing a setting somewhere. Do you know how to fix this?
Title: Re: Multiple images, different shadows
Post by: Oshyan on July 24, 2014, 12:01:34 AM
This is either due to not using GI caching, or needing to use GI/Ray Detail Region Padding (Advanced tab in the renderer). I would try GI caching first, if you're not already using it. The correct approach is to calculate separate GI caches for all 6 views, then use "equal blend within range" with a frame value of 6 to render *all* frames. Here's documentation on GI Caching:
http://www.planetside.co.uk/wiki/index.php?title=Terragen_2_Global_Illumination#Rendering_with_GI_cache_files

If you are using the free version and don't have access to GI Caching, then try increasing GI Prepass Padding, start with 0.5 and see if it helps, then 1. If no difference, then try Ray Detail Region Padding, again starting with 0.5, then 1.

- Oshyan
Title: Re: Multiple images, different shadows
Post by: Matt on July 25, 2014, 04:39:52 PM
Since you're rendering a 360-degree scene and you want the shadows to be the same in all renders, there's a new mode in Terragen 3.1 that can solve this problem. On the renderer's Advanced tab, change the "Ray detail region" to "360 degree detail (highest)".

From the 3.1 change log:

Quote"Ray detail region" has 2 new modes to choose from called "360 degree detail (optimal)" and "360 degree detail (highest)". With "360 degree detail (highest)", the subdivision detail of ray traced displacements is uniform in all directions around the camera position, even behind the camera. "360 degree detail (optimal)" is similar except that detail is reduced by a factor of 3 behind the camera, with a smooth transition from front to back. In both of these modes "ray detail region padding" has no effect. They do not work with orthographic cameras. With perspective cameras they should help to avoid popping shadows and other ray traced displacement artifacts originating from outside the camera's field of view. However, beware that this will increase render times greatly so if there are any ray traced reflections appearing on objects with high curvature or displacement.

Oshyan's advice about GI cache files will also be useful to keep the general lightness of the shadows the same in each image.

Matt
Title: Re: Multiple images, different shadows
Post by: freezurbern on July 25, 2014, 06:27:40 PM
I combined all of those tips, and it worked! Yay! Thank you.
Title: Re: Multiple images, different shadows
Post by: bobbystahr on July 26, 2014, 09:47:39 AM
I'll say it again..."What a great forum for a great program!"