I keep seing a weird effect in DS which I can't get rid of. When I use a black and white pattern image in the bump setting for a metal texture, the metal texture is no longer smooth around the lines of the pattern. It goes kind of dimpled and looks 'messy'.  I'm at a loss to work out why this is happening. The bump image is pure b&w with no feathering of the black lines.I created the pattern using one of the Photoshop standard shapes.

Does anyone have any idea why this happens?

It could very well be the SIZE of the map you made in photoshop.  If it's a small pixel size, for a large object UV, you are going to have feathering and distortion no matter the pattern.

I usually work rather large, over 2000 pixels x 2500 pixels for objects and save the map the same size.  That may work for you.

Hi Darwinsmap, thanks for the response. I've tried that also but am not seeing any improvement.

I've attached animage of what the surface looks like close up - you can see the smooth part of the texture where there is no bump (bottom left), but around the bump pattern it looks 'messy' rather than seeing a clean pattern imprint. This is at a low bump setting too, and I've tried varying all the bump settings.

By contrast if I just paint some straight black lines on white and use that for a bump pattern there is no problem.

I'm stumped! 

I don't see the attachment, sorry.

Wait- did you use a brush shape, rather than just a general use brush to make the design you wanted for the bump?  I've found that in a few things I've worked on for M4 that had the same issue-blurred edging when used in the system.  I don't know if it's the pixel edge of the brush stamp/shape that is used, or if it's something to do with the actual brush SETTINGS when it's used.

Have you tried using a vector-art shape rather than a brush stamp/shape?

And hey-  no problem in the answer, even if I've not helped.  At times it can take two heads or more to figure out the answer to an issue.........

...IF you can get a response at all on some forums.

ooops, forgot to attache the image - here it is. As can bee seen there's a kind of dimpled effect around the shape lines. It's almost as though the pattern was not created with smooth brush lines.  I'm seeing the effect from patterns I've made using photoshop shapes and also from store bought patterns. So it could be a  photoshop brush problem/shape problem. When you look at the patterns in photoshop though they look fine.

Very frustrating.

I see what you're saying here, and yes- I've seen this with numerous made and bought brush shapes and patterns.

Try using a freebie vector art on a dummy bump map and see if you have the same issue?

Hi, thanks very much for the suggestion. I tried some free vector patterns but still getting the same effect. I wish I could find a way round this.

Bah- that just sucks, pardon my verbiage.  My last suggestion is to out and out paint the design using a basic ps brush as a test to see if that works better.  I'm sorry I'm not more help, honestly.  Have you tried high-end (or what I consider so) purchased brushes such as Ron's sets (Deviney) as a test run to see if they do the same thing?  As you suspect, it may be how the brush shape was made to begin with.  Perhaps there is another set, from a different vendor or free (high-resolution, mind you) that you can use for the same effect.

If straight lines are OK it does sound like the anti-aliasing on the curves - you haven't said what size your images are. Using 16 bit grey-scale images might help too.

i get rid of that in psp7 by adjusting my brightness and contrast settings. this gives sharp edges without the dimples.

the image has to be pure black and white with no grey at all unless you want it to go smoothy from the high to the low part of the image

Hi, thanks for the responses and suggestions.

I've found that ramping up the contrast on what appears to be a clean b&w image actually shows up additional speckles and marks on patterns I've bought or created myself (even when I was careful to produce clean straight lines) . So it's possible to a certain degree to fill these bits with white to get rid of them. But even so the lines still don't show as 'clean' when used for a bump map in DS. I've tried creating a shape using the pen tool and also using a basic brush. Whatever I try I still get some of the same effect.

I'm thinking now maybe it's more of a question for the photoshop forum...

What resolution is your map (not PPI, which is irrelevant, but how many pixels wide and tall)? More to the point, roughly how many pixels does the bit you show take up on the map?

Hi Richard, I've tried using small resolution (600x600) and larger (2000x2000). It didn't seem to make a difference:(

You did refresh the images in DS (or use a different name) when trying the higher resolution version? And it was a genuine higher resolution version, not the lower res upsampled?