Shadow

Haddock · Post by **Haddock** » Mon Feb 16, 2004 7:27 pm

I'm using volumetric shadow casted by an animated character, and the shadow is rendered correctly on the environment, but unfortunatelly also on the character : the part of the character which is not facing to the light, is much darker than the same character without shadow (I hope my explanations are clears).
In the drawAll() method, if I change the order, by render first, normal objects except the character, then shadows and then the character, everything is correct, because the character is rendered after its shadow.
So, is there something I am doing wrong? Or do I have to declare my character as a transparent object (rendered after shadows) or do I have to rewrite drawAll() method, as I did ?
By the way, shadows are consuming a lot of CPU power, so I am about to implement a solution where I have two models for my character : one for the render, and one, a much lower level version of the first one, for the shadow.

niko · Post by **niko** » Wed Feb 18, 2004 7:14 am

Haddock wrote: the part of the character which is not facing to the light, is much darker than the same character without shadow

Isn't this correct? I mean, if the character is selfshadowing, it getting darker again where shadows fall on it. A solution to disable selfshadowing is how you did it. Another would be to call the render()-Method directly from the Character Scene Node.

Haddock · Post by **Haddock** » Sun Feb 22, 2004 7:08 am

To explain my issue properly, here is an example taken directly from the last Techdemo:

Without shadows

With shadows

You can notice on the second image that the character has some artifacts (on its right upper arm and rigth part of the body), because it is affected by the its own shadow, and because the character is rendered before its shadow.
I don't think this is a driver issue. If I'm not wrong, in order to calculate the shadow, the engine extrudes, opposed to the light, a volumetric shadow and everything that is inside this volume is shadowed. Unfortunatelly, a part of the character is in this volume, and then it is affected by the shadow.

julio · Post by **julio** » Thu Feb 26, 2004 2:28 pm

and do we have the possibilty to have shadows with an alpha color ?
because in the demo the shadwos were not transparent but
in a solid black color !

is this a way to determine an alpha value for shadows ?

Tyn · Post by **Tyn** » Thu Feb 26, 2004 3:53 pm

The shadows in that last screenie look fairly transparent, unless work is really getting to me

thesmileman · Post by **thesmileman** » Fri Feb 27, 2004 2:11 am

Haddock, I am really really having a hard time seeing what you are talking about the second picture looks like a correctly rendered shadow to me.

julio · Post by **julio** » Fri Feb 27, 2004 12:29 pm

yes in second picture the shadow is transparent on floor !
i 'm going to launch again the demo to see it !

i was persuaded the shadow was in a black solid color !

Tels · Post by **Tels** » Sun Feb 29, 2004 4:29 pm

Ugh! On Linux the techdemo looks radically different! The textures are grey-blue! The shadows are black. Mipmapping seems to be missing.

I'll uploaded a screenshot, is this normal for the OpenGL/Linux path on a Geforce3?

See second set of shots:

http://bloodgate.com/perl/irrlicht/techdemo.html

Best wishes,

Tels

niko · Post by **niko** » Mon Mar 01, 2004 11:36 am

Currently this is normal for linux, but I am working on it.

buhatkj · Post by **buhatkj** » Mon Mar 01, 2004 3:07 pm

i think it might be that he just want likes spot shadows on the ground, not truly dynamic shasows...
-Ted

Tels · Post by **Tels** » Mon Mar 01, 2004 6:13 pm

niko wrote:Currently this is normal for linux, but I am working on it.

Cool

)

Irrlicht Engine

Shadow

Shadow

Re: Shadow

yeh man i thought that shadpw looked great...