#Bump Maps
11 messages in this thread
Hi there,
Question for ya. When using bump mapping how does the bumpiness slider
actually affect the map? I mean does a value of 1 mean that the maximum
depth of the bumps will be 1 or is there 1 a pixel depth between each
successive level of gray in the bump map? For instance, a grayscale bump
map I created for use as a bathrrom tile has white,black and 4 shades of
gray in between them. So, do I need a value of 6 to get the full effect of
the map or will a value of 1 create "bumps" between each of the different
gray levels?
Thanks for any help Dave Mennenoh 71561,2343
When using a bump map, you've got a full 8-bits of luma within the bitmap
itself (shades of 0-255) to use to set the bumpiness. This is before you
even start thinking about the percentage slider in Medit. It's important
to use as much bandwidth in the bitmap as possible, and then the slide just
will affect the amount of the map that's mixed in to the rest of the
material. Note that when you use an sxp as a bumpmap (like dents or
noise), the slider's full 0-100 range is very effective, but when you use a
bitmap as a bumpmap, the truly useful range is more like 0-20.
– G
Thanks for the info. So, say if I wanted a "bathroom tile" with the grout
indented like it should be, what would be the most effective way? I was
under the assumption that if you wanted to make just the grout recessed I
would make the tile then make the bump map – white where the tile is and
black where the deepest portion of the grout was. Then use intermediate
shades of gray to get the smooth effect of the tile being rounded at the
edges. Is this correct?
Dave
That's exactly the way I'd do it. Then, try a setting of 10-15% for the
bump map slider.
– G
PMJI, but i was experimenting recently with a tile bump map that had color
gradations where the tile would curve to meet the grout. The problem i ran
into was that the bump map itself would appear on the curved part, in other
words, regardless of lighting conditions, the edges of the tile were gray.
I used it with a texture map for the tile color and with bump settings from
1 to 15. What might cause this to happen?
Steve Ormonde
Since the bump map was applied to the texture map, it sounds like the
renderer was trying to interpolate the bumped edge, and that's what was
making the edge gray. I can't really say much more than that without
seeing the specific geometry.
– G
I'll email you the bump/texture map. If you get some time, you can take a
look at it, no rush.
Steve Ormonde
Actually I was also getting the same sort of problem. The gray scale bump
map ending up in the rendered tile. I ended up using a value of 1 for the
bump map slider, it corrected the problem to the point where it was
tolerable though. Any recommendations?
Dave Mennenoh
Dave,
I resorted to using a texture map only. Looks great, until you get an
extreme close-up of the tile, then it looks, well, less than realistic.
Gary seems to think it's due to the bump/texture combo. If you can have
the grout and tile the same color, try using just the bump. Or maybe,
scale/copy the object down about 99.75%, use a combo bump/opacity map
(opacity to make the joints transparent) and color the scaled object the
grout color? might work…
Steve Ormonde
What program do you guys use for creating your maps? I've heard of so many
different paint programs that sound like they could work. Will they all
essentially accomplish the same thing?
Thanks, Chris
It depends upon the requirement… For 8-bit maps and animated flic maps,
we use Animator Pro. When we need to do 24-bit work, Photostyler is the
current program of choice, but the most powerful programs for creating
24-bit maps (IMHO) are Ron Scott's Hi-Res QFX and Time Arts' Lumena.
– G