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Re: [Manta] r2077 - trunk/Interface


Chronological Thread 
  • From: Thiago Ize <thiago@cs.utah.edu>
  • To: ollie@lanl.gov, "'manta@sci.utah.edu'" <manta@sci.utah.edu>
  • Subject: Re: [Manta] r2077 - trunk/Interface
  • Date: Fri, 15 Feb 2008 15:48:33 -0700
Li-Ta Lo wrote: 
On Fri, 2008-02-15 at 14:44 -0700, Thiago Ize wrote:
  
yeah, I see the surface acne along the shadow boundary. I'm guessing
what is happening here is a self shadowing artifact. If that's the
case, then I would have expected my raising of T_EPSILON from 1e-5 to
1-4 would have actually improved this problem for you.

When you hit 'c', what is the camera position? Also, what are the
dimensions of your scene? (Some of the acceleration structures will
print the bounding box for you during the build).

    

A similar one showing the problem has bbox and camera:

Make_scene args: 2

DynBVH::preprocess START (11035 objects)

DynBVH build time: Total (0.01881)
object_ids initialization (0.001255)
build (0.016756)
updateBounds (0.000799)
BBox = (-72.7012 -56.3921 254.661, -62.4312 -44.3239 264.465)

pinhole( -eye -62.0498 -49.0895 256.554 -lookat -67.5659 -50.3581
259.562 -up -0.176268 0.98021 0.0900966 -hfov 60 -vfov 60
-normalizeRays )
Alas, that looks reasonable to me. Does modifying the value of T_EPSILON to 1e-2, 1e-3, 1e-4, etc... in Interface/Parameters.h give something that works?

  

    
By the way, if you want nice looking images, try super sampling by
adding one of the following command line arguments:
  -imagetraverser deadline"()" or
    

  

  

This one fixed the problem as is actuall twice faster (fps). It is
normal to show the mosaic when I rotate the scene, right?
  



It's not actually twice as fast. What deadline does is progressively
render the frame. So it will first render a coarse version. Then it
will cast some more rays and render a more refined version. And so on
until you've actually cast 1024 rays per pixel. That means the image
should look really pretty if you wait a while and don't move the
camera. The blockyness you see when you move the camera is manta having
to start from scratch again and render a coarse version. The fps will
actually always be the same with deadline. But if you have a really
slow to render scene you'll see the blockyness for more time since
manta is taking lower to refine (so we trade quality for
responsiveness).



  
What is an image traverser?

  



It determines how the primary rays should be cast. Deadline does it
progressively, others will cast rays in a horizontal line, some in a
square tile, and so on.



Thiago




























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