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#ActualL. Spiro

Posted 24 February 2013 - 05:19 PM

Yep, the BRDF needs both the PI and the division by NDotL, while the implementation in a standard shader doesn't need those.

Shaders do need NdotL.  Division by PI should be precalculated and sent to the shader—IE the light values the shader receives should already have been divided by PI.
 
 

What's the computation for the X and Y parameters that BRDF Explorer uses for aniso distributions? Are they tangent/bitangent vectors?

Yes, but in screen space (in pixel shaders) they often resolve to the directions [1,0,0] and [0,1,0].  Remember, they depend on your eyes, not the orientation of the object.

 

 

L. Spiro


#4L. Spiro

Posted 24 February 2013 - 05:13 PM

Yep, the BRDF needs both the PI and the division by NDotL, while the implementation in a standard shader doesn't need those.

Shaders do need NdotL.  Division by PI should be precalculated and sent to the shader—IE the light values the shader receives should already have been divided by PI.
 
 

What's the computation for the X and Y parameters that BRDF Explorer uses for aniso distributions? Are they tangent/bitangent vectors?

Yes, but in screen space (in pixel shaders) they often resolve to the directions [1,0,0] and [0,1,0].  Remember, they depend on your eyes, not the orientation of the object.


For your daily “LOL”, after I voted up every single post in this topic some idiot actually came in here an voted down both of my (and only my) prior posts.
Votes don’t matter so much but if you were going to choose 2 of my posts to vote down, seriously? These ones? In a topic where you only vote-up or leave?
I nearly cracked a rib. What a moron. laugh.png

 

Anyway I have a few more +4’s to give so…

 

 

L. Spiro


#3L. Spiro

Posted 24 February 2013 - 05:13 PM

Yep, the BRDF needs both the PI and the division by NDotL, while the implementation in a standard shader doesn't need those.

Shaders do need NdotL.  Division by PI should be precalculated and sent to the shader—IE the light values the shader receives should already have been divided by PI.
 
 

What's the computation for the X and Y parameters that BRDF Explorer uses for aniso distributions? Are they tangent/bitangent vectors?

Yes, but in screen space (in pixel shaders) they often resolve to the directions [1,0,0] and [0,1,0].  Remember, they depend on your eyes, not the orientation of the object.


For your daily “LOL”, after I voted up every single post in this topic some idiot actually came in here an voted down both of my prior posts.
Votes don’t matter so much but if you were going to choose 2 of my posts to vote down, seriously? These ones? In a topic where you only vote-up or leave?
I nearly cracked a rib. What a moron. laugh.png

 

Anyway I have a few more +4’s to give so…

 

 

L. Spiro


#2L. Spiro

Posted 24 February 2013 - 05:11 PM

Yep, the BRDF needs both the PI and the division by NDotL, while the implementation in a standard shader doesn't need those.

Shaders do need NdotL.  Division by PI should be precalculated and sent to the shader.
 
 

What's the computation for the X and Y parameters that BRDF Explorer uses for aniso distributions? Are they tangent/bitangent vectors?

Yes, but in screen space (in pixel shaders) they often resolve to the directions [1,0,0] and [0,1,0].  Remember, they depend on your eyes, not the orientation of the object.


For your daily “LOL”, after I voted up every single post in this topic some idiot actually came in here an voted down both of my prior posts.
Votes don’t matter so much but if you were going to choose 2 of my posts to vote down, seriously? These ones? In a topic where you only vote-up or leave?
I nearly cracked a rib. What a moron. laugh.png

 

Anyway I have a few more +4’s to give so…

 

 

L. Spiro


#1L. Spiro

Posted 24 February 2013 - 05:09 PM

Yep, the BRDF needs both the PI and the division by NDotL, while the implementation in a standard shader doesn't need those.

Shaders do need NdotL.
 
 

What's the computation for the X and Y parameters that BRDF Explorer uses for aniso distributions? Are they tangent/bitangent vectors?

Yes, but in screen space (in pixel shaders) they often resolve to the directions [1,0,0] and [0,1,0].  Remember, they depend on your eyes, not the orientation of the object.


For your daily “LOL”, after I voted up every single post in this topic some idiot actually came in here an voted down both of my prior posts.
Votes don’t matter so much but if you were going to choose 2 of my posts to vote down, seriously? These ones? In a topic where you only vote-up or leave?
I nearly cracked a rib. What a moron. laugh.png

 

Anyway I have a few more +4’s to give so…

 

 

L. Spiro


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