Azurik: Rise of Perathia - Revision history

DaveX: image uploaded

2017-06-27T03:17:10Z

image uploaded

JayFoxRox at 14:57, 22 May 2017

2017-05-22T14:57:05Z

JayFoxRox: JayFoxRox moved page Game:Azurik: Rise of Perathia to Azurik: Rise of Perathia without leaving a redirect

2017-05-22T14:56:51Z

JayFoxRox moved page Game:Azurik: Rise of Perathia to Azurik: Rise of Perathia without leaving a redirect

JayFoxRox: JayFoxRox moved page Games/Azurik: Rise of Perathia to Game:Azurik: Rise of Perathia

2017-05-22T14:48:07Z

JayFoxRox moved page Games/Azurik: Rise of Perathia to Game:Azurik: Rise of Perathia

JayFoxRox: Testing template

2017-05-22T14:40:04Z

Testing template

JayFoxRox at 13:37, 29 March 2017

2017-03-29T13:37:20Z

JayFoxRox: Temporary hack

2017-03-29T13:30:39Z

Temporary hack

New page

=== Known tricky behaviour ===

==== Skinning code / Shader rounding mode ====

This game suffers from issues with non-exact rounding in the shaders which do the skinning / skeletal animation.

[[File:http://i.imgur.com/tpmLpjP.png]]

IIRC Code is like:

A0 = c[113].x + c[113].z = 18
*do stuff with c[96+A0] to c[98+A0]*

A0 = c[113].x + c[113].z = 21
*do stuff with c[96+A0] to c[98+A0]*

A0 = c[113].y * v2
*do stuff with c[96+A0] to c[98+A0]*

c[113] is vec4(15, 765, 3, 0). 765 = 3*255.
v2 is GL_UNSIGNED_BYTE, normalized => v2 = raw/255.
A0 = 765 * raw/255 = 3*raw.

This should all be working, but it's not. NV2A expects round-to-zero, GLSL and other modern graphic APIs have it undefined..
It works with A0 += 1.0/255.0 as a temporary hack

@@ Line 6: / Line 6: @@
 This game depends on correct GPU rounding. If an emulator suffers from issues with non-exact rounding in the shaders which do the skinning / skeletal animation the character models will be very broken.
-[[File:http://i.imgur.com/tpmLpjP.png]]
+[[File:Azurik--Rise-of-Perathia--bugged.png]]
 IIRC Code is like:

← Older revision		Revision as of 14:57, 22 May 2017
Line 1:		Line 1:
	{{Game}}		{{Game}}
−
	=== Known tricky behaviour ===		=== Known tricky behaviour ===

← Older revision		Revision as of 14:40, 22 May 2017
Line 1:		Line 1:
		+	{{Game}}
		+
	=== Known tricky behaviour ===		=== Known tricky behaviour ===

← Older revision	Revision as of 14:56, 22 May 2017
(No difference)

← Older revision	Revision as of 14:48, 22 May 2017
(No difference)

@@ Line 3: / Line 3: @@
 ==== Skinning code / Shader rounding mode ====
-This game suffers from issues with non-exact rounding in the shaders which do the skinning / skeletal animation.
+This game depends on correct GPU rounding. If an emulator suffers from issues with non-exact rounding in the shaders which do the skinning / skeletal animation the character models will be very broken.
 [[File:http://i.imgur.com/tpmLpjP.png]]
@@ Line 22: / Line 22: @@
   A0 = 765 * raw/255 = 3*raw.
-This should all be working, but it's not. NV2A expects round-to-zero, GLSL and other modern graphic APIs have it undefined..
+This should all be working, but it's not. [[NV2A/Vertex Shader]] does round-to-zero. Behaviour for GLSL and other modern graphic APIs is undefined..
-It works with A0 += 1.0/255.0 as a temporary hack
+To work around this rounding issue <code>A0 += 1.0/255.0</code> can be used as a temporary hack