Bitmap Filtering and Blur Values

[Dave Buckley]

Been playing around with materials/textures today and noticed something strange.

 

Take my bump map for example, If I set my bitmap filtering to 'None' and reduce the blur blur value to 0.01, it gives no effect, if I then change the filtering to 'Pyramidal' it gives me the effect I want.

 

Any one know why it does this?

 

The quality of the map/rendered effect, appears to diminish when reducing blur below 0.1 when filtering is set to 'None'

[John Dollus]

yes. Neil covered this a couple years ago. It's a good read-

http://www.neilblevins.com/cg_education/bitmap_blurring/bitmap_blurring.htm

 

Note: have no idea if turning off the blur for certain vray map circumstances still affects the render time.

[Dave Buckley]

Hmm, I saw that when looking for the answer but it doesn't answer my question unfortunately.

[Chris MacDonald]

If I set my bitmap filtering to 'None' and reduce the blur blur value to 0.01, it gives no effect, if I then change the filtering to 'Pyramidal' it gives me the effect I want.

 

Any one know why it does this?

 

This is because when it's set to "none" no filtering is taking place at all.

 

 

The quality of the map/rendered effect, appears to diminish when reducing blur below 0.1 when filtering is set to 'None'

 

The quality of the map in the material editor, perhaps. This is because there aren't enough antialiasing samples to resolve any noise introduced by reducing the amount of filtering. Provided you've got good enough antialiasing settings your production render should be just fine (if not better quality) by having filtering set to none/a low value - however this may add time to your renders because the computer sees the additional (non filtered) information as high frequency noise.

 

http://www.macviz.blogspot.co.uk/2013/08/bitmap-tip.html

Edited February 2, 2016 by Macker

[Dave Buckley]

Ok makes more sense, but essentially I have a detailed wood texture, good grain detail. I would expect, filtering set to 'None' and blur on 0.01 to give me maximum detail from my texture when rendered, but what I'm finding is, when I go lower than 0.1 the detail slowly disappears to the point where at 0.01 it looks like I have no bump map applied at all