Golf ball
43 messages in this thread
Does anyone have any tips on how to model a golf ball in LW2.0? Those little
dimples are killers!
The ball will be seen close to the camera and it may or may not spin – so I
don't think any sort of mapping is in order… But if someone knows of a way I
can achieve realistic looking results with mappings.. my ears are wide open.
If I can't do it with mappings I'll have to model the dimples… How?
Any thoughts on this would be appreciated.
Thanks, Mark.
P.S. Also, I have to put a phrase across the surface of the ball. It should
dip into the dimples just like a real golf ball.
Sounds to me like the logical way to do it is with a bump map. It would
be hell to actually model it as well as fairly polygon intensive. The way
to get a good looking dimple is to go into DPaint and create a light gray
to white spherical gradient on a white background. Repeat this pattern
over the whole image and make sure all the edges have no dots halfway on
them. Try using this as your bump map. Of course, you'll have to
practice with the sizes. Also, the logo can be drawn right on the map to
also simulate bumps. In a bump map the luminance (brightness values) of
the image determine how bumpy the surface is. White is raised while black
is not. That's why the map should be a white background with gradient
spheres centering into grey or black. This will make them appear pressed
in. You could also make the colors reversed and use 'Negative Image' in
the Bump map panel.
Thanks John. I beleive you're saying that I should make one dimple in DPaint
and pattern that across the sphere in LW… right? Or should I make one
dimple, pattern that in DPaint to create many bumps, and then slap it on the
sphere? I guess I'll try both. Thanks for your comments.
Hi Mark,
Yes, I was reffering to making one image with a lot of dimple patterns on
it. Make sure none of the dimples touch any edges for a seamless wrap.
Good luck!
JG
Might one not get a better image with ToasterPaint? or at least an AGA dpaint
with 256 gray levels. If you got to close to a dithered dpaint 16color map, you
might notice it. Also make the sphere big, so there's lots o color in the
range area.
You are absolutely correct.
🙂
JG
The method John Gross outlines in his message to you should work except
that you will probably end up with a seam where the edges of the bump map
meet. I'm not sure if this will work as I dont have a Toaster but you
might try wrapping the bump map around a pair of hemispheres. Start with a
sphere in the modeler. Use the volume mode to cut and paste half of it to
another layer. Save one of the hemispheres as ball.1 and the other as
ball.2. Next go into layout and load both of the hemispheres. Map the bump
map onto each of the hemispheres using a spherical map. Now group the 2
hemispheres together so they move as 1 object. (Can you do that with
LightWave?)
The idea is that the seam where the edges of the bumpmap meet would be on
the side of the sphere that you cut out in the modeler.
I'll e-mail you a picture that might make this a little more
understandable.
I'm not quite sure what you mean, Jeff. I'll look at that pic and get back
with you.
Thanks for your comments.
Jeff,
The seam issue is why I said that you should make sure that all of the
image edges are the solid white background color. That way when they wrap
and meet, you will have a seamless image around the ball.
JG
The problem with trying to wrap a square image onto a round ball is that
it will NEVER turn out right. Imagine all of the dimples are the same size
and there are 15 across per line. You do a spherical wrap onto the ball.
There are 15 dimples around the equator but near the poles the edges of
the image will overlap OR the dimples will have to change size.
Whichever happens it won't look right.
I once saw an brush that was designed to be mapped onto a sphere to create
a basketball for Imagine. The brush was NOT square. it had a really odd
shape so that all of the edges would meet but not overlap when it was
wrapped onto the sphere. I'm not sure how LightWave would react to a
non-square brush though.
Sit down and have a REALLY close look at the pattern on a golf ball and
see if you can figure out an easy way to duplicate that pattern on a flat
image so that you will be able to wrap it and have the pattern look right.
Even the method that I suggested won't have QUITE the right look but it
should look closer if it works.
Jeff,
Try making a brush that's just a row of dimples, and make each slice of
your golfball a different surface. Then change the mapping sizes to get
the right look using that image as a cylindrical or spherical bump map for
each layer. Might work.
Also, try making a square white brush with a round hole in it. Use the
outline function in DPaint (kybd o) as you select darker and darker greys,
and make it change faster at first. This would mean one outline at the
first grey, two at the second, three at the third, and so on until the
hole is filled. This will give you a tapered bowl shaped dimple rather
than a cone shaped one.
Use that grey blob as a brush for your row of dimples. Make sure that the
number of pixels of white on the two ends of your row equals the number of
pixels between each dimple, and make the whole thing an even multiple of
64 pixels wide. This will make sure that it maps nicely.
Let us know how it comes out!
… Nate, Emerald Video.
I Animate – because – I am a Nate!
Nathan,
Your suggestion won't work properly. Making the dimple the single dimple is
simple enough… Creating many of them in one map to be wrapped spherically is
the problem.
Also, take a good look at a golfball as Jeff suggests. There are no clean rows
of dimples. The dimples are packed together and wrapped perfectly around the
ball – as if each dimple were the center with other dimples surrounding it.
It's tough!
Mark,
I don't have a golf ball handy, but is it possible that the dimples a
packed in some sort of a pattern? Sort of like atoms in a crystal lattice?
If so it might be possible to make a brush map of this 'unit cell' and
spherically map it, using tiling. The map would look something like:
.
.P P
. F
.P P
.
The P's are basically quarters of the F dimple in the center.
Jim
It's tough to recognize a pattern on the ball. I've made one similar to the
way you describes a week ago. I was a repeating pattern that eventually formed
what seemed to be five dimples surrounding one dimple. Multiples of these were
sandwiched inbetween the spaces in the original 6 dimple pattern in a gear-like
organization.
If the pattern is built correctly a new pattern emerges… a triangle of
dimples surrounding one dimple where any dimple could be the center dimple.
This pattern (if not correct) seems to simulate the dimples on the ball very
well. Now, if I could map it perfectly around the ball …
Did you map with just the brush or a full image of the entire sphere? I'm
working on this huge space station object. It needed a 'hull plate'
pattern to be mapped onto a spherical habitat module. I made a hexagon
tile and stamped 6 down around the original. Then I cut out a square brush
through the centers of the outer 4 hexagons. With the tiling set to large
numbers, like 30 or so, it looked pretty good, even at the poles.
Jim, I mapped the entire picture (after patterning the brush).
I've been trying to visualize your hexagon layout. How do you cut
thru the four outside hexagons if there are actually six? Does the
brush you cut have four long legs and two short ones? How are you at
ASCII drawing 🙂
I went back and looked at it again….I see that two of the outer hexagons
were redundant. So….
__
1 / \ 2 If you start with the center hexagon, pick it up and plop 3
\__/ 4 down copies on sides 1-4. The top and bottom are unneeded.
__ __ Now, cut out a square with corners in the exact centers of
/1 \__/2 \ hexagons 1,2,3 and 4.
\__/ \__/
/3 \__/4 \
\__/ \__/
..__..
|_/ \_| Now that I look at it, I see I goofed when I described is as
|.\__/.| a square. It's actually a rectangle.
If instead, you add the top & bottom hexagons, then cut from the center of
the top face of #1 to the center of the bottom face of #4 you get a brush
that's closer to being a square.
_…._
\__/ Actually, I like this one better. It looked pretty good
_/ \_ tiled onto a 10km sphere at about 60×60. Since I have a
\__/ large tube comming out both poles,distortion at the poles is
_/..\_ not a problem.
Jim… Plain Geometry, nothing fancy.
Mark,
Hey, you're right about the dimples on a golf ball. Not only aren't they
all in a row, I can't even recognize a pattern on the one I found.
How about making a square brush of dimples in a random(?) pattern, and
using it to fill an hourglass shape in the shape fill mode, pick up a
square chunk of it, and use that as your map? You may be able to fudge
the edges enough to get a repeating pattern. Squash the top and bottom if
necessary.
Well, good luck, and sorry for the bum dope. If you get it figured out,
why don't you UL it so we can all see the results.
… Nate, Emerald Video.
I Animate – because – I am a Nate!
Ah, yes. I've done that. The wrapping is the problem.
II have modelled a golf ball. It took about two and one-half hours. Probably
less time than the discussions on the subject! I will upload in a day or so. It
is not a regulation PGA ball but it will do. It consists of about 10k of
polygons and was an interesting challenge.
It is not mapped, but rather has actual dimples that can be rendered very close
without much trouble. The shading in some areas gets a little flaky when you
shoot the thing in full screen but I am happy with it.
Jim Roof
That would be great, Jim. Let me know when you upload it.
Just take a golf ball and cut the cover off. Flatten the carcass and then
digitize it. Now just wrap it around any sphere.
–Paul < Motorola Inside >
That won't help much paul. Actually creating a pattern to wrap is not much of
a problem… wrapping it around a sphere is. It's just as much of a problem
as you would have if you tried to do what you suggested.
Cutting the cover off the ball would not yield a nice, flat surface. How do
you get material molded as a sphere to lay flat without cutting slots in it?
Even if you could… you have the same rectangle to sphere mapping problem that
we've all been talking about.
Mark,
It might ust be cheaper in the long run to buy the object from Viewpoint.
I believ their fully dimpled golf ball is about $400.
wmc – via Autopilot!
Mark,
Have you checked out the golfball in Lib 10 in Amiga Arts forum? It's the one
I did and it may suit your purposes.
Jim Roof
Oops! I've been hit by a drive-by golf ball message!! (Sorry, I'm not the
one who needed it, but I did see it in the libs. Mark will probably
too.)
wmc – via Autopilot!
That's pretty expensive for an object. Don't you think?
Not Really. Modeling IS ALOT of work. BTW if you think $400 for a Model is
alot you'd pass out when you see the price for their Complete Skeleton
Model.
I dunno – never bought one, but they apparently do a brisk business
selling them. Course if you saw the ball and amortized that over the hours
it took to create it, the artist/designer is not geting all that much.
wmc – via Autopilot!
I don't have a Toaster so I can't try this. My suggestions for
LightWave are all theory based on my experience with other packages.
It has however occured to me that if a person was willing to rename
every polygon of the golf ball with a different name and map a SINGLE
dimple to each one the spacing should be perfect and there should be
no distortion. LightWave CAN make a ball with square polygons rather
than triangles right? It shouldn't take much more memory than a
single bump map since LightWave only uses one image and just pastes
it on other surfaces.
Actually, you would not want 4-sided polys for the golf ball. The polar regions
make very narrow trapezoids and the very top polar polys ARE triangles. I
suggest your method but with a level three tesselation as the primitive. It
will be a lot of work but this might well be the ticket to the party.
Jim Roof
That wouldn't work because of the way LW maps. some of the polygons that
were not on x,y or z axes would wrap slightly off.
JG
Jeff,
Lightwave makes spheres that are either rectangular along the equator, but
triangles on the poles, or tesselations, which are all triangles. Maybe
the secret would be in using those triangles, since they may look to be in
a similar pattern to the golf ball.
… Nate, Emerald Video.
I Animate – because – I am a Nate!
Jeff,
For a spherical image map, make sure you image is a multiple of 16 pixels
wide. LW doesn't do so well on spherical wraps that are not divisible by
16 in width.
wmc – via Autopilot!
Well, the bump map looks OK. I used ProFills to make a seamless map. The only
problem is that a planer mapping distorts the image along the sides of the
sphere. The spherical mapping distort it around the poles (causing the same
number of dimples around the equator to appear near the poles).
I guess this will do – compared to the modeling alternative.
Thanks, Mark.
Hi Mark,
Lot of good tips in this thread…here's something else to throw into the
stewpot.
You came across that "pinching" problem at the poles of a spherical map. In
Photoshop there's a filter called "Polar to Rectangular" that helps in changing
a flat image to something suitable for spherical mapping. The result has fewer
dots at top, more at bottom, and the ones at the bottom/equator are stretched
— dimples are equidistant and properly shaped when bump-mapped to a sphere.
I'm not sure which of the Amiga paint programs duplicates this
function…perhaps someone else can suggest?
Another approach is Steve Worley's basketball example that Jeff alludes
to…it's in Steve's book "Understanding Imagine 2.0", but I don't really
understand the explanation. (The map *is* square, though, it's just the
contents that are deformed.)
Hope this helps!
John D.
John,
The 'Polar to Rectangular' operation in Photoshop sounds like it would solve
the problem perfectly. But I don't have Photoshop. It is a PC product? Who
makes it? ZSoft?
If anybody knows how I can acheive a 'Polar to Rectangular' image operation
with Amiga based progs, let me know.
Thanks, Mark.
Photoshop 2.5 is by Adobe. There is both a Mac and IBM version.
Miguel ——– AP, AP, and away!
Mark,
I have done a golf ball (for an animation for a country club) -looks good even
when moving. I used bump maps for the dimples + a texture map of the club's
logo.
I'd be happy to send a copy of the LW files, in the interest of Toaster good
will (or maybe even a little credit <g>) Let me know if you want me to dig it
up!
The only real problem I ran into was getting the right number of spherical
mapping multiples for the dimples.
Good Luck!
Luke Montgomery,
CompVid, Kansas City
Luke,
'The only real problem I ran into was getting the right number of spherical
mapping multiples for the dimples.'
Did you solve this? If so, and you still have a copy of the bump map, I would
be interested in it. E-Mail me if you have it.
Thanks, Mark.
I have ul'd the golf ball in lib 10 in the Amiga arts forum. It looks
pretty good. The dimples may not be quite dense enough but
considering the # of polys I think it's dense enough!
Jim, thanks a lot for the golfball upload. I rendered it and it looks quite
good. I'm not going to use it, however — the dimples aren't very dense (as
you mentioned).
I'm going to go the bump map route. I build nice pic of dimples. Now all I
need is to stretch the top and bottom portions (while leaving the middle
untouched) and wrap it. Photoshop has an operator that will do this but I
don't have access to Photoshop. I'll write a rediculous script in ADPro to
painfully build the new image one scanline at a time if I have to.
Thank you very much for your upload. That's an impressive piece of effort.