Talk:Shadow mapping

message: praetor_alpha 17:33, 3 October 2005 (UTC)

message: This statement is completely incorrect, so I removed it:
"The rough edges of shadow maps are sometimes referred to as "shadow acne"."
Shadow acne occurs when the depth parameter is too low relative to the shadowmap resolution, and a surface begins to self-shadow.  It usually creates dark bands where there should be none.  Pixellated edges of shadows has nothing to do with "shadow acne".
-Josh
I disagree about the merging with Shadow Maps for two reasons:
*Shadow maps are static, while shadow mapping is dynamic.  Shadow maps are loaded once and usually never again, while shadow mapping is constantly updating.
*Shadow mapping involves comparing depth values, rather than just putting a brighter/dimmer shade on a polygon.
** Oh, I see what you are trying to say; you mean light maps? These are precomputed maps; but shadow mapping is dynamic and is usually run inside a GPU. 
I agree about merging with Shadow Maps since they are both the same, or even simply linking Shadow Maps to this page. Its just unfortunate someone wrote a (small and inaccurate) article about static shadow mapping (or light mapping) and called it 'Shadow Maps' and someone else wrote a larger and more detailed one about dynamic shadow mapping and called it 'Shadow Mapping'. The underlying theory is always the same, working out shadows and storing them in some texture map, then recalling that information to reconstruct shadows. Whether you use depth maps or color maps, do it dynamically or statically, it all falls under the loose description of shadow mapping in my opinion.
Jheriko 22:08, 22 January 2006 (UTC)
thread_title: Untitled

message: Shadow mapping involves finding the world coordinates of a point, projecting it back into light space and then performing a compare. These steps and also the disregard of vertex/pixel shaders which are extremely crucial (also the current hardware capability allows everything to be performed in real-time) is missing in this article.
Until one of us updates to reflect this, I am adding a stub/cleanup for this page. -- dormant25, Feb 8, 2006 Moreover, the information given is not in the right side of "highly technical" nor in the "amateur level" - it is more of a passing information...
:I noticed that too. The whole "pass two" step contains basically know information. "Some magic happens" would be almost as good. I'll see if I can learn what is going on there from the cited NVIDIA articles and incorporate it into the article. - Rainwarrior 17:45, 26 July 2006 (UTC)
replies: text: Ahh, okay. The shadow map is a collection of depth values which will be used for a visibility test. When drawing a fragment, project that fragment's location into the light's space, and it will have a depth that can be compared against the shadow map. If it's further away than the depth in the shadow map, the fragment is in shadow. The actual matrix transformation will be something like a translation and rotation from the light to the eye (maybe a scaling as well, the light-view frustrum doesn't have to be the same size), and the trickiest part is turning the projected coordinates into a depth value that you can compare against the shadow map (I haven't quite figured that part out yet). - Rainwarrior 18:25, 26 July 2006 (UTC)
replies: text: I rewrote that section of the article, and cleaned up the rest as best I could. How is it now? - Rainwarrior 19:30, 30 July 2006 (UTC)
thread_title: More information needed to adhere to quality standards

message: http://developer.nvidia.com/attach/6769, the second external link, is broken at the time I write this - August 8th, 2011. Anyone have a substitute link?
--DangerOnTheRanger (talk) 22:11, 8 August 2011 (UTC)
thread_title:  NVIDIA link broken 

message: An maybe-odd-seeming question here. Is there a "mainstream unix" object known as a "shadow buffer" (or is that another name for a shadow table)?  If so, I think a disambig on this page should point to it - although not a full disambig page, as the graphics term 'shadow buffer' is most certainly the more used meaning.  I've run into the term in the Apple Newton ROM (CShadowBufferSegment, along with CBufferSegment) - so it is altogether possible that it is NOT a standard UNIX term (the NOS implementation of the stdc libs is strange and certainly not complete).  But I have no idea whether there is a UNIX term 'shadow buffer' at all - which is how I ended up here.. Jimw338 (talk) 17:49, 3 July 2012 (UTC)
thread_title:  OT? - Disambig with "shadow buffer" CS term