Jump to content

  • Log In with Google      Sign In   
  • Create Account

FREE SOFTWARE GIVEAWAY

We have 4 x Pro Licences (valued at $59 each) for 2d modular animation software Spriter to give away in this Thursday's GDNet Direct email newsletter.


Read more in this forum topic or make sure you're signed up (from the right-hand sidebar on the homepage) and read Thursday's newsletter to get in the running!


#ActualL. Spiro

Posted 22 February 2013 - 07:12 PM

I personally like how Ashikhmin-Shirley looks since the diffuse term changes with the view angle.  This is true for Oren-Nayar as well but it is less noticeable.

We presented a more accurate and more efficient Oren-Nayar last year at SIGGRAPH (see links provided by Matias Goldberg: “Beyond a Simple Physically Based Blinn-Phong Model in Real-Time (+ slides)”)

 

I am not so much into Cook-Torrance as it seems to result in overpowering speculars, at least for me.  Since I don’t have a way to actually specify reflectance at normal incidence on my models for my engine yet it could be that I just don’t have a very good conversion of specular power to reflectance at normal incidence.  But checking images online they do also seem to have much wider and area-encompassing speculars.

 

 

I would use our improved Oren-Nayar model by default for low-end devices.

If computing power is removed from the equation I would stick with Ashikhmin-Shirley coupled with the layered material system that was also presented in the same link as above (of course, only when appropriate—not all surfaces need a layered-material system).

 

Here are results of Ashikhmin-Shirley:

LSBRDF19.png

This shot in particular sold me on Ashikhmin-Shirley with the nice transition of oranges over the hood of the car.

 

LSBRDF20.png

No ambient-occlusion was used on the bumper.  It is just the natural result of Ashikhmin-Shirley.

 

More…

 

 

L. Spiro


#1L. Spiro

Posted 22 February 2013 - 07:10 PM

I personally like how Ashikhmin-Shirley looks since the diffuse term changes with the view angle.  This is true for Oren-Nayar as well but it is less noticeable.

We presented a more accurate and more efficient Oren-Nayar last year at SIGGRAPH (see links provided by Matias Goldberg: “Beyond a Simple Physically Based Blinn-Phong Model in Real-Time (+ slides)”)

 

I am not so much into Cook-Torrance as it seems to result in overpowering speculars at least for me.  Since I don’t have a way to actually specify reflectance at normal incidence on my models for my engine yet it could be that I just don’t have a very good conversion of specular power to reflectance at normal incidence.  But checking images online they do also seem to have much wider and area-encompassing speculars.

 

 

I would use our improved Oren-Nayar model by default for low-end devices.

If computing power is removed from the equation I would stick with Ashikhmin-Shirley coupled with the layered material system that was also presented in the same link as above (of course, only when appropriate—not all surfaces need a layered-material system).

 

Here are results of Ashikhmin-Shirley:

LSBRDF19.png

This shot in particular sold me on Ashikhmin-Shirley with the nice transition of oranges over the hood of the car.

 

LSBRDF20.png

No ambient-occlusion was used on the bumper.  It is just the natural result of Ashikhmin-Shirley.

 

More…

 

 

L. Spiro


PARTNERS