Filter Forge - Rotatable Sphere Snippet by ThreeDee

Active Topics Search

CorvusCroax

Posts: 1175
Filters: 17

Rotatable Sphere Snippet by ThreeDee
http://www.filterforge.com/filters/6488.html

Posted: October 8, 2008 10:56 pm

Details E-Mail

CorvusCroax

Posts: 1175
Filters: 17

awesomeness in offsets.

Posted: October 8, 2008 10:57 pm

Details E-Mail

rgoer

Posts: 46

I have a question about one part of this snippet, this offset step in particular:

How does the orange-ish bit of the checker pattern come back after it was absent from the green-and-purple-only offset step?

Posted: October 11, 2008 3:10 pm

Details E-Mail

ThreeDee

Lost in Space

Posts: 1140
Filters: 89

Quote
rgoer wrote: I have a question about one part of this snippet, this offset step in particular: How does the orange-ish bit of the checker pattern come back after it was absent from the green-and-purple-only offset step?

My somewhat theoretical answer is that there is an ever-so-small (were talking floating-point math last digit level here) inaccuracy introduced in the offset method of enlarging images. That doesn't show up in the previous step, but it is just below the threshold area of the second offset step (that creates the polar mapping) to make it back into the image. In other words, I believe that there is a disappearingly small slice of that orange and blue pattern in the previous step that you could make visible by enlarging the top (or bottom) edge of that image infinitely. Since that polar mapping step essentially stretches the edge pixel infinitely, it reappears.

That's what I assume.

Posted: October 11, 2008 4:10 pm

Details E-Mail

Mike Blackney

Posts: 352
Filters: 54

This is old, but it's super awesome. I'm looking at quickly mocking up some planet textures to see what they'd look like in 3d and this is perfect for it, and lightning fast.

Posted: December 25, 2011 8:43 pm

Details E-Mail