January 30, 2012, 03:12:55 pm
Yes, i can see but you'll agree it's like putting a plaster on a booboo.
I hope it'll get fixed in the next update
The problems stem from the way shadow maps are used to generate shadows. In essence a shadow map is just an images which shows the view from the light source but instead of the color it contains the distance to the light. To turn this into a shadow we simply test if a certain pixel is visible from the light.
The problem occurs in some cases when for example a surface strarts casting shadows upon itself. This is is because a shadow map only has pixels while the actual surface is a sloped polygon. The pixel is an oversimplification of the slope so in the final rendr you will see a triangle because one half of the pixel thinks it's visible while the other thinks it's not.
To remove this error we offset the pixel depth so the entire pixel contains the closest distance and not de distance in the center. This works perfectly because you won't see any false shadows anymore. In some cases, however, you can see gaps. The solution is to change the sun angle to reduce the slope, increase the shadow resolution to decrease the size of the pixels or you can mess around with the offset settings untill the problem disappears.
So actually there's no fix. We can however provide more control which will allow you to eliminate this type of artefact.