Author: rambetter

Date: Tue Dec 28 23:20:32 2010
New Revision: 378
Updating notes on regression tests.  They are "mostly sort of fixed".  Won't
be fixed for good until I look at the last bit of code that has not been
examined yet, which is the plane intersection code.  I want the errors to be
much less than they are now, even though the disappearing_sliver* tests are
now working.

diff --git a/regression_tests/q3map2/disappearing_sliver/README.txt b/regression_tests/q3map2/disappearing_sliver/README.txt
index 491540303893c8556d056331563e9f50c9f1225d..a65d9203cc80596488e9b468f2cb031d34ae4534 100644 (file)
--- a/regression_tests/q3map2/disappearing_sliver/README.txt
+++ b/regression_tests/q3map2/disappearing_sliver/README.txt
@@ -46,7 +46,7 @@ And we get rid of the recpirocal length ilength altogether.  Even the
 slightest math errors are magnified in successive calls to linear algebra
 functions.
 
 slightest math errors are magnified in successive calls to linear algebra
 functions.
 

-The change described above was commmitted to GtkRadiant trunk as revision r363.
+The change described above was commmitted to GtkRadiant trunk as revision 363.

 
 
 POSSIBLE SIDE EFFECTS:
 
 
 POSSIBLE SIDE EFFECTS:


@@ -162,3 +162,22 @@ It seems that FixBrokenSurface() should be fixed to completely fix the case
 where there are two close points, and should report the surface as fixed.
 This might be a destabilizing change however, so if this is indeed fixed, it
 may make sense to activate the fix only if a certain flag is set.
 where there are two close points, and should report the surface as fixed.
 This might be a destabilizing change however, so if this is indeed fixed, it
 may make sense to activate the fix only if a certain flag is set.

+
+
+MORE NOTES:
+===========
+
+As stated above, the accuracy after revision 363 is:
+
+  (67.000229 -1021.998657 0.000000)
+  (88.000175 -891.999146 -767.997437)
+  (133.999146 -1014.998779 0.000000)
+
+A further change was committed for a related problem in revision 377.  After
+this change:
+
+  (66.99955750 -1022.00262451 0.00000000)
+  (87.99969482 -892.00170898 -768.00524902)
+  (133.99958801 -1015.00195312 0.00000000)
+
+The results look similar with respect to the amount of error present.

diff --git a/regression_tests/q3map2/disappearing_sliver2/README.txt b/regression_tests/q3map2/disappearing_sliver2/README.txt
index 55f9b51dbe3b8b4a94f77bdf1df36205831c619d..ffa12be5678ee509ca7a93ab141d6131b2bb277a 100644 (file)
--- a/regression_tests/q3map2/disappearing_sliver2/README.txt
+++ b/regression_tests/q3map2/disappearing_sliver2/README.txt
@@ -16,7 +16,7 @@ SOLUTION TO PROBLEM:
 
 It was discovered that BaseWindingForPlane() in polylib.c did some sloppy
 mathematics with significant loss of precision.  Those problems have been
 
 It was discovered that BaseWindingForPlane() in polylib.c did some sloppy
 mathematics with significant loss of precision.  Those problems have been

-addressed in commit revision 371.
+addressed in commits to revisions 371 and 377.

 
 
 POSSIBLE SIDE EFFECTS:
 
 
 POSSIBLE SIDE EFFECTS:


@@ -67,17 +67,27 @@ is this:
 As you can see, all points but one have an increase in accuracy.  This is
 still not accurate enough in my opinion, but is a step in the right direction.
 
 As you can see, all points but one have an increase in accuracy.  This is
 still not accurate enough in my opinion, but is a step in the right direction.
 

+After the fix committed in revision 377, which is a further attempt to address
+BaseWindingForPlane(), we get the following accuracy:
+
+  (6784.00000000 16241.00000000 -1722.00000000)
+  (6144.00000000 16083.00000000 -1443.00000000)
+  (6144.00000000 16122.00000000 -1424.00000000)
+
+It's just a fluke for this particular case, but obviouly revision 377 looks
+favorably upon this regression test, because there is zero percent error.
+

 
 MORE NOTES:
 ===========
 
 I attempted to improve upon revision 371 by streamlining the code in
 
 MORE NOTES:
 ===========
 
 I attempted to improve upon revision 371 by streamlining the code in

-BaseWindingForPlane() some more.  Those attempts were committed as r375.
-After revision 375:
+BaseWindingForPlane() some more.  Those attempts were committed as revision
+375.  After revision 375:

 
   (6784.09375000 16241.01757812 -1722.04687500)
   (6144.00000000 16082.99414062 -1443.00390625)
   (6144.00000000 16122.00000000 -1424.00097656)
 
 Revision 375 has since been reverted (undone) because of the loss in
 
   (6784.09375000 16241.01757812 -1722.04687500)
   (6144.00000000 16082.99414062 -1443.00390625)
   (6144.00000000 16122.00000000 -1424.00097656)
 
 Revision 375 has since been reverted (undone) because of the loss in

-accuracy.
+accuracy.  Revision 377 is a fix for those failed attempts.

diff --git a/regression_tests/q3map2/disappearing_sliver3/README.txt b/regression_tests/q3map2/disappearing_sliver3/README.txt
index 9fda8b0cc249e861ebc6c83e69e3c96f3b50af95..839bd692f1d57eafbcea608a6169432cae0c0398 100644 (file)
--- a/regression_tests/q3map2/disappearing_sliver3/README.txt
+++ b/regression_tests/q3map2/disappearing_sliver3/README.txt
@@ -14,4 +14,36 @@ compile for any Q3 mod.
 SOLUTION TO PROBLEM:
 ====================
 
 SOLUTION TO PROBLEM:
 ====================
 

-None yet.  Probably due to sloppy math code.
+More work has been done to BaseWindingForPlane() to make it more accurate.
+This function is in polylib.c.  The changes to fix this regression test were
+committed in revision 377; however, those changes are not "good enough".
+
+
+IN-DEPTH DISCUSSION:
+====================
+
+This is the problem triangle:
+
+  In ParseRawBrush() for brush 0
+      Side 0:
+          (6144.000000 16122.000000 -2048.000000)
+          (6144.000000 16083.000000 -2048.000000)
+          (6784.000000 16241.000000 -2048.000000)
+
+Computed winding before fix:
+
+  (6784.16406250 16241.04101562 -2048.00000000)
+  (6144.00000000 16122.00976562 -2048.00000000)
+  (6144.00000000 16083.00000000 -2048.00000000)
+
+Obviously the 6784.16406250 is beyond epsilon error.
+
+After revision 377:
+
+  (6783.85937500 16240.96484375 -2048.00000000)
+  (6144.00000000 16121.99218750 -2048.00000000)
+  (6144.00000000 16083.00000000 -2048.00000000)
+
+Even though this fixes the regression test, the error in 6783.85937500 is
+still greater than epsilon (but fortunately in the opposite direction).  So
+I don't consider this test case to be fixed quite yet.

diff --git a/regression_tests/q3map2/sparkly_seam/README.txt b/regression_tests/q3map2/sparkly_seam/README.txt
index 4ffab57c738cb3aa3b9acfd913f1dd36d33c05f1..3c54feb596ed970735fa4405739a158768d84255 100644 (file)
--- a/regression_tests/q3map2/sparkly_seam/README.txt
+++ b/regression_tests/q3map2/sparkly_seam/README.txt
@@ -15,4 +15,7 @@ SOLUTION TO PROBLEM:
 ====================
 
 None yet.  The problem is likely caused by sloppy math operations (significant
 ====================
 
 None yet.  The problem is likely caused by sloppy math operations (significant

-loss of precision).
+loss of precision).  This bug pops in and out of existence with every other
+commit at the moment.  The problem is likely caused by the operations in the
+brush winding computation (where the planes are intersected with each other).
+I have not gotten around to addressing that code yet.