smoothing the shadow mapping of t2

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primalsac
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Joined: Sat Aug 14, 2004 9:58 am

smoothing the shadow mapping of t2

Post by primalsac »

Can this be done? My shadows in game engine are looking a little pixelated, Is there some way to make them smooth? Im using t2 windows build and i have a geforce fx 5200. Thanks

z3r0_d
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Post by z3r0_d »

increase the resolution of the shadow buffer, and your screen resolution [it will end up less than or equal to the size of the smallest side of your blender window... if your blender window is 1024x760 your largest depth buffer could be 760x760, but because it needs to be power of two, it will be 512x512...]

other than that, blender would have to start oversampling [tuhopuu2 is no longer in active development]

mpan3
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Post by mpan3 »

Just want to share my experience with T2, actually i tried it on 2 graphic card, my current Radeon 9600 (WinXP, Catalyst 4.12) and a Geforce6800 Ultra :twisted: (WinXP, 69.xx?) Needless to say, the fps on the 6800 is way higher than my 9600, but there is also an image quality difference:

On the 9600, it seems the shadow is clipped as a 1bit texture, i don't know the proper term but the edge is not only pixelated, but sharp. Like when you use the "threshold" function in photoshop (the shadow is either "on", or "off"). On the 6800, there is some interpolation going on and when the shadow is magnified, the edge is soft. :wink:

also, the rendered shadow size seems to be dependent on the window size,not the "shadow resolution" slider in the lamp panel.

z3r0_d
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Post by z3r0_d »

mpan3 wrote:Just want to share my experience with T2, actually i tried it on 2 graphic card, my current Radeon 9600 (WinXP, Catalyst 4.12) and a Geforce6800 Ultra :twisted: (WinXP, 69.xx?) Needless to say, the fps on the 6800 is way higher than my 9600, but there is also an image quality difference:

On the 9600, it seems the shadow is clipped as a 1bit texture, i don't know the proper term but the edge is not only pixelated, but sharp. Like when you use the "threshold" function in photoshop (the shadow is either "on", or "off"). On the 6800, there is some interpolation going on and when the shadow is magnified, the edge is soft. :wink:
I noticed that when comparing mesa to my 9600 too...

mesa:
Image
my radeon 9600 se:
Image
mpan3 wrote:also, the rendered shadow size seems to be dependent on the window size,not the "shadow resolution" slider in the lamp panel.
if you set it to smaller than the window size then it does make a difference... I said that it can't be larger than the window size in my last post

alien-xmp
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Post by alien-xmp »

Shadow mapping is a 1 bit technique, you can only tell if the pixel is in shadow or out of shadow. It sounds like the GF 6 is doing bilinear interpolation, which would be nice.

I'll look at porting some of the T2 stuff to T3 when I get some time & when NVIDIA release new Linux drivers with EXT_framebuffer_object. (EXT_framebuffer_object will remove the shadow map size must be less than screen size limit)

You can look at smoothing the shadows by using a pixel shader, but the FX5200 doesn't really have enough fill rate for that.

mpan3
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Joined: Wed Mar 24, 2004 7:16 pm

Post by mpan3 »

alien-xmp wrote: I'll look at porting some of the T2 stuff to T3 when I get some time & when NVIDIA release new Linux drivers with EXT_framebuffer_object. (EXT_framebuffer_object will remove the shadow map size must be less than screen size limit)
Please do... I wonder how much longer I have to wait until Blender has shadow and multitexture functions.

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