Planetside Software Forums

General => Terragen Discussion => Topic started by: bigben on July 13, 2014, 03:21:38 AM

Title: Render options for spherical camera.
Post by: bigben on July 13, 2014, 03:21:38 AM
Had a bit of free time to read the wiki while waiting for a largish spherical render to complete (still have half a day or so to go). Watching the render at the horizon and reading the page on ray tracing (http://www.planetside.co.uk/wiki/index.php?title=Ray_Trace_Objects_and_Defer_Atmosphere/Cloud#More_technical_details (http://www.planetside.co.uk/wiki/index.php?title=Ray_Trace_Objects_and_Defer_Atmosphere/Cloud#More_technical_details)) I'm thinking that ray trace everything might be faster in this case(?) Has anyone done any testing with this? 
1. There are areas of atmosphere rendered below the horizon in the areas behind the camera (left and right quarters of the image). Defer atmosphere helps with that.
2. "... the ray tracer does not have the problem of overdraw that sometimes happens with the micro-polygon rasteriser"... lots of potential with a wide horizon
3. "... surfaces which are viewed at glancing angles, such as terrain or water near the horizon, tend to have micro-polygons that appear smaller than a pixel even thought they would appear much larger if they had been facing the camera."

Given that there is a lot of horizon in a spherical render and the progress of the render here is painfully slow it seems to fit the criteria for using ray trace everything. Does this sound right?

Title: Re: Render options for spherical camera.
Post by: jdent02 on July 14, 2014, 09:36:26 PM
Defer atmosphere is great to use when you don't have objects to raytrace and there's a lot of horizon in the image.
Title: Re: Render options for spherical camera.
Post by: Oshyan on July 16, 2014, 02:58:40 AM
Your theory seems potentially sound, but for equivalent detail Raytrace Everything is quite a bit slower, so you'd have to have a *lot* of overdraw happening for it to be a net gain.

- Oshyan
Title: Re: Render options for spherical camera.
Post by: bigben on July 16, 2014, 06:59:10 PM
Quote from: Oshyan on July 16, 2014, 02:58:40 AM
Your theory seems potentially sound, but for equivalent detail Raytrace Everything is quite a bit slower, so you'd have to have a *lot* of overdraw happening for it to be a net gain.

- Oshyan

Thanks Oshyan. That certainly matches what I found out, I was testing against a render with detail=1