displace node wrong y derivative + easy bugfix :) #31472

Closed
opened 2012-05-15 18:33:56 +02:00 by Ervin Weber · 5 comments

%%%A small typo in node_composite_displace.c makes the node to calculate a wrong y derivative.
With high Y SCALE values the output becomes somewhat blurred depending on the input vector direction.

To fix sustitute this line:
d_dy = vecdy- [x] * ys;
with:
d_dy = vecdy- [x] * ys;

At least every version dating back to 2.53 is affected. It seems that the displace node is the least used node in Blender!
The fix corrects the node behaviour as it was in 2.49b.

Attached a gif file showing the problem and the source blend file .
A black circle is displaced 30px in different directions, the bug is proportional to the difference between the x and y components of the displacement vector.%%%

%%%A small typo in node_composite_displace.c makes the node to calculate a wrong y derivative. With high Y SCALE values the output becomes somewhat blurred depending on the input vector direction. To fix sustitute this line: d_dy = vecdy- [x] * ys; with: d_dy = vecdy- [x] * ys; At least every version dating back to 2.53 is affected. It seems that the displace node is _the least_ used node in Blender! The fix corrects the node behaviour as it was in 2.49b. Attached a gif file showing the problem and the source blend file . A black circle is displaced 30px in different directions, the bug is proportional to the difference between the x and y components of the displacement vector.%%%
Author

Changed status to: 'Open'

Changed status to: 'Open'

%%%note: if this patch is applied be sure to check for other use of qd_getPixel in the same file.%%%

%%%note: if this patch is applied be sure to check for other use of qd_getPixel in the same file.%%%

%%%svn blame tells me r39941, assigning to lukas toenne%%%

%%%svn blame tells me r39941, assigning to lukas toenne%%%
Member

%%%Thanks for the fix, applied to SVN!%%%

%%%Thanks for the fix, applied to SVN!%%%
Member

Changed status from 'Open' to: 'Resolved'

Changed status from 'Open' to: 'Resolved'
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Reference: blender/blender#31472
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