Ways of making a shadow

$L!M · Post by **$L!M** » Mon Apr 10, 2006 4:52 pm

Hi again
I have few questions:
1. Are there any methods of making "soft-edge" shadows in irrlicht?
2. How can I make really FAST shadows, which wouldn't slow down FPS?
3. What is the best way of outdoor scene lighting? How many light sources should I use?
4. How to make shadowcasting only from light source I want.

P.S. addShadowVolumeSceneNode method is very slow imho

P.P.S. Excuse my bad english

Guest · Post by **Guest** » Mon Apr 10, 2006 5:42 pm

For outdoor, as well as indoor scene, you can use lightmaps. I would only use dynamic shadows for characters or objects.

$L!M · Post by **$L!M** » Mon Apr 10, 2006 6:00 pm

Anonymous wrote:For outdoor, as well as indoor scene, you can use lightmaps. I would only use dynamic shadows for characters or objects.

I don't know what is lightmaps

Okay, How can I obtain shadow of tree, which consists of few vertical polygons without backface culling and *.png texture with alpha channel?

$L!M · Post by **$L!M** » Tue Apr 11, 2006 5:23 am

Answer my questions, please

finger007 · Post by **finger007** » Tue Apr 11, 2006 10:32 am

Hi,

for lightmaps please use google/wikipedia for technique and then the forum here for methods and programs. It depends on your OS and modelling/rendering-package...
Basically its a 'shadow-texture' used with your existing one. There has been written a lot about it

.

Your question about tree-shadow: It can be done using lightmaps too. But if your tree is moving, your shadow will stay 'frozen' to the position the lightmap has been rendered to. Then its time for dynamic shadows again...so read a bit about lightmaps - it's really easy to understand.

Cheers,
finger007

Amt0571 · Post by **Amt0571** » Tue Apr 11, 2006 2:21 pm

Lightmaps are basically textures which contain the shadows. The only problem with lightmaps, as finger007 says, is that they're static, so they're only useful for static objects (for example, a wall).

Their advantage relies in that they're very fast and very high quality, since they are pre-rendered.

I don't know how to do them in other software, but if you use 3D studio you will have to use the "render to texture" in the render menu to create the lightmaps.

$L!M · Post by **$L!M** » Tue Apr 11, 2006 3:57 pm

Thnx for explanation.
I'm using 3dsmax for modeling and rendering.

I have more questions now
1. How can I make static shadow (which looks like skylight shadow) under the car....One way is to make polygon under the car with alpha channel, but in this case part of my shadow will disappear, when the hills of terrain will be situated between the car's wheels

2. How to make reflection such as raytrace one in 3dmax? I know that cubemaps or something like this should be used, but i don't know exactly, how can I realize this with irrlicht

$L!M · Post by **$L!M** » Tue Apr 11, 2006 3:59 pm

Forgot to say, that I myt car wouldn't be static.

$L!M · Post by **$L!M** » Wed Apr 12, 2006 7:49 am

please please please. I need help

Aukecomps · Post by **Aukecomps** » Wed Apr 12, 2006 1:57 pm

google?
you might try moving a shodow object (dunno if your car is jumping)

for the soft-edge shadows: dunno if it works, but you might want to try placing a bunch of lights in a group