PDA

View Full Version : Thickness



^DaNiEl^
10-08-2004, 03:21 AM
Hi, what's the best method to calculate the thickness of an object ?

Jan
10-08-2004, 05:04 AM
What exactly do you mean? Or, what do you want to achieve?

There are several ways to calculate the thickness of an object, depending on which thickness you need.

And learn to give that information right away, so people donīt need to ask what you actually want, every time.

Jan.

Coconut
10-08-2004, 05:19 AM
I use ruler to measure the thickness of an object. If I don't have a ruler with me, I will take off my shoe, and use my foot to measure it. Since I always remember the length of my foot, I then multiply it by the number of footsteps.
Keep in mind people usually have one foot longer than the other one, so stick with the same foot all the times, to reduce the errors.

^DaNiEl^
10-08-2004, 07:01 AM
I need it because i'm doing subsurface scattering. Till now i used 1.0 as thickness value, it looks good but it's not correct. Can anyone help me ?

sBibi
10-08-2004, 07:46 AM
there is an NVIDIA paper that talks about this, you have to render the front faces depths, then subtract the backfaces depth from them, you get the perpixel thickness in the final buffer (this requires a few passes on older hardware...)

(I don't know if it's the "best" method though...)

dorbie
10-08-2004, 09:20 AM
Yea this:

http://download.nvidia.com/developer/S ...gonVolumes3.pdf (http://download.nvidia.com/developer/SDK/Individual_Samples/DEMOS%5CDirect3D9%5Csrc%5CFogPolygonVolumes3%5Cdoc s%5CFogPolygonVolumes3.pdf)

If you look at the citations you'll see Radomir Mech's original work cited. You can see that paper here:

http://www.acm.org/jgt/papers/Mech01/

About as useful as a lead balloon unless you have the journal though.

Here's something even earlier (I think Radomir cites this), fortunately it's available online:
http://nothings.org/computer/vfog/index.html