Darkplaces lighting
From Blood Wiki
(Difference between revisions)
(→Light methods and effects) |
(→Shadow mapping vs Stencil shadows) |
||
| Line 31: | Line 31: | ||
* Takes less CPU time (as construction of shadow volumes is not required) | * Takes less CPU time (as construction of shadow volumes is not required) | ||
* Distance-based LOD (far lights rendered with lower shadowmap resolution) | * Distance-based LOD (far lights rendered with lower shadowmap resolution) | ||
| − | * Shadow edges are not | + | * Shadow edges are not sharp |
== Comparison of different lighting methods == | == Comparison of different lighting methods == | ||
Revision as of 18:32, 27 July 2012
This page is not finished
You can help by editing and extending it.
You can help by editing and extending it.
Darkplaces engine uses combined lighting model. Several lighting methods are implemented to give best results at cases they are aimed for.
Contents |
Light models
Darkplaces using several lighting models, most of them are set globally:
- Phong lighting model - generic and default lighting model
- Fake light - a developer-only mode which is forced on non-lit maps (ones which was compiled and didnt get LIGHT phase). This is infinite realtime light that is cast from eye position.
- Cel shading - a phong lighting model with altered shading.
- Fullbright - no lighting applied
Light methods and effects
There is 4 lighting methods used in Darkplaces:
- Vertex lighting - static lighting, aimed at big counts of simple surfaces
- Lightmaps - static lighting, aimed at surfaces that receives shadows from static objects
- Lightgrid - static lighting, aimed at moving entities
- Realtime lighting - fully dynamic lighting (each light is a separate pass), aimed at switchable and moving lightsources that lights moving entities
Additionaly, Darkplaces supports a number of lighting effects:
- Coronas - aimed to simulate glow around lights, which looks good on small and medium size lights
- Planar shadows - each entity cast one shadow on the floor (or by global vector)
- Customized modellight - lightgrid-sampled model lighting could be replaced with QuakeC
- Fog - global fog and global volumeric fog (with height set) are suppored
Shadow mapping vs Stencil shadows
Stencil shadow volumes is a shadow rendering method Darkplaces used in pre-2010. Since 2010 shadow mapping was implemented by Eihrul.
Shadowmapping have a number of advantages over shadow volume rendering and is considered to replace it:
- It is faster to render (especially on complex area maps)
- Takes less CPU time (as construction of shadow volumes is not required)
- Distance-based LOD (far lights rendered with lower shadowmap resolution)
- Shadow edges are not sharp
Comparison of different lighting methods
| Task | Vertex lighting |
Lightmap | Lightgrid | Realtime lighting |
|---|---|---|---|---|
| Details | Low | Medium | Low | High |
| Render speed | Fastest | Fast | Fastest | Slow |
| Precomputation time | Small | Long | Medium | N/A |
| RAM usage | Low | High | Low | Low |
| Shadows | No | Yes | No | Yes |
| Number of lights | Large | Large | Large | Small |
| Surface-based effects | ||||
| Bumpmapping | Yes | Yes | Yes | Yes |
| Specular | Yes | Yes | Yes | Yes |
| Cubemap filters | No | Partial | No | Yes |
| Per-light diffuse/ambient/specular scale | No | No | No | Yes |
| Non-point 'area' lights | Yes | Yes | Yes | No |
| Light styles | No | No | No | Yes |
| Moving lights | No | No | No | Yes |
| Global illumination | ||||
| Precompulation time | Long | Very long | Long | N/A |
| Rendering speed | N/A | N/A | N/A | Slow |
| Quality | High | High | High | Low |
| Used to light | ||||
| Map surfaces | Yes | Yes | No | Yes |
| Static BModels | Yes | Yes | Yes | Yes |
| Moving/rotating BModels | No | No | Yes | Yes |
| Animated models | No | No | Yes | Yes |
Console variables
r_shadow_realtime_world : Enabled realtime lighting of world lights (stored in external .rtlights file) r_shadow_realtime_dlight : Enabled realtime lighting of dynamic lights (created by entities) r_shadow_* : A group of cvars to control realtime lighting r_shadow_shadowmapping : Enables shadowmapping which replaces default shadow volume-based lighting r_shadow_shadowmapping_* : A group of cvars to control shadowmapping r_shadows_* : A group of cvars to control planar shadows r_showlighting : Show areas lit by dynamic lightsources. Useful for finding out why some areas of the map render slowly (bright orange = lots of passes, slow) r_showshadows : Show areas covered by shadow volumes. Useful for finding out why some areas of the map render slowly (bright blue = lots of passes, slow). Only matters if using shadow volumes.
