Sihn opened this issue on Jul 24, 2001 ยท 4 posts
Sihn posted Tue, 24 July 2001 at 5:53 AM
I have a habit of creating large scenes and then rendering (from the director's view) a portion of that scene. I'm wondering, as a scene is rendered, are those areas out of the view of the camera also getting rendered? If this is a dumb question, put it to lack of sleep. s
jval posted Tue, 24 July 2001 at 8:06 AM
No. In the real world rays of light bounce off everything and some of them eventually enter our eyes thus allowing us to see. In raytracing it is the opposite. Think of it as rays leaving your eyes and hitting everything in sight, but only in sight. This means a lot less rays to calculate and alo means that things outside your view are ignored and effectively do not exist as far as the rendering process is concerned.
Cheers posted Fri, 27 July 2001 at 2:34 AM
jval, I have to disagree with you there...as geometry outside the field of view is taken into account, for shadow calculations etc. If you place an object outside the FOV, and the light is in the right place you will see that it will still cast a shadow within your scene. With radiosity renderers/global illumination renderers the calculations for objects outside the scene are even more complex. I admit that the objects outside the FOV are not physically rendered, but processor intensive calculations for them still take place that will slow render time down. Cheers
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jval posted Fri, 27 July 2001 at 6:53 AM
Hi Cheers. Absolutely geometry outside the fov can indirectly affect the render. But that was not the question and the answer to "...are those areas out of the view of the camera also getting rendered?" remains "no". As far as raytracing is concerned things outside of the fov do not exist. However, the effects such things may have within the FOV do exist. In your example the shadow itself becomes the object to be included in the render, not the item causing the shadow. There are real world parallels. For instance, you do not have to see the orchestra to hear the concerto they may be playing. The two exist as separate, though related, things. I suspect we disagree not so much in concept as in semantics. However, computers tend to be picky in their instructions so I must follow suit (grin).