Vinyl Record

Vinyl Record

Post by Darrel Hoffma » Wed, 25 Jun 2003 02:28:23



Trying to get the effect seen on an old vinyl LP where the light reflects in two bands on opposite sides of the record and the rest
is mostly black.  I gave it a bump map to simulate the grooves, (tiled gradient with cylindrical UV map) and the texture has high
Spec and Glossiness.  Thought that would be enough, but it just isn't producing satisfying results.  The highlight either covers the
entire surface or it looks extremely faceted.  If I up the polygon count on the model (a modified Tube primitive) I can get the
faceting effect down, but I have to go to over 100 segments on the tube to get a decent look, and that's FAR more polygons than this
simple shape deserves.  There's got to be an easier way to do this, but I'm stumped.  (Yes, I thought about making a diffuse map
that has the highlight already on it, but that won't work in this case because it's animated.  It's got to be a specular thing.)

...And while I'm thinking of it, how the heck would you do a CD?  Same specular effect only with rainbow colors...  Hmm...  That's
not for this project, but it'd be cool to try...

 
 
 

Vinyl Record

Post by Brizo » Wed, 25 Jun 2003 03:59:49


| Trying to get the effect seen on an old vinyl LP where the light
| reflects in two bands on opposite sides of the record and the rest is
| mostly black.  I gave it a bump map to simulate the grooves, (tiled
| gradient with cylindrical UV map) and the texture has high Spec and
| Glossiness.  Thought that would be enough, but it just isn't
| producing satisfying results.  The highlight either covers the entire
| surface or it looks extremely faceted.  If I up the polygon count on
| the model (a modified Tube primitive) I can get the faceting effect
| down, but I have to go to over 100 segments on the tube to get a
| decent look, and that's FAR more polygons than this simple shape
| deserves.  There's got to be an easier way to do this, but I'm
| stumped.  (Yes, I thought about making a diffuse map that has the
| highlight already on it, but that won't work in this case because
| it's animated.  It's got to be a specular thing.)
|
| ...And while I'm thinking of it, how the heck would you do a CD?
| Same specular effect only with rainbow colors...  Hmm...  That's not
| for this project, but it'd be cool to try...

first question (LP's): anisotropy

second question (CD's): incidence angle color gradient, and anisotropy
perhaps

should be fine then

 
 
 

Vinyl Record

Post by Darrel Hoffma » Wed, 25 Jun 2003 06:07:50


Quote:> first question (LP's): anisotropy

> second question (CD's): incidence angle color gradient, and anisotropy
> perhaps

I tried anistropy, but the groove pattern didn't show up very well with that technique.  It pretty much just looked like a flat disc
with an eliptical highlight on it, not really what I want.  The highlight should be wider towards the edges of the disc and narrower
in the middle.

Quick Google search example:
http://www.lausd.k12.ca.us/Verdugo_HS/j4fun/stars/martinz3.gif

Not exactly the effect I'm going for, but closer than anything I've gotten.  I'm surprised a simple grooved bump map isn't enough in
this case...

 
 
 

Vinyl Record

Post by Brizo » Wed, 25 Jun 2003 18:46:50


|| first question (LP's): anisotropy
||
|| second question (CD's): incidence angle color gradient, and
|| anisotropy
|| perhaps
|
| I tried anistropy, but the groove pattern didn't show up very well
| with that technique.  It pretty much just looked like a flat disc
| with an eliptical highlight on it, not really what I want.  The
| highlight should be wider towards the edges of the disc and narrower
| in the middle.
|
| Quick Google search example:
| http://www.veryComputer.com/
|
| Not exactly the effect I'm going for, but closer than anything I've
| gotten.  I'm surprised a simple grooved bump map isn't enough in this
| case...

bump mapping would work, but the amount of AA required would make it a
* to render quickly.. or pretty high AA and a much larger image to
scale down aswell as anisotropy

have you tried scanning an LP, never tried it but it might get a more
realistic bump pattern out of it and not need as much AA to smooth it out
perhaps?

keep trying though, your on the right track

 
 
 

Vinyl Record

Post by Everett Hicke » Wed, 25 Jun 2003 22:35:56




> || first question (LP's): anisotropy
> ||
> || second question (CD's): incidence angle color gradient, and
> || anisotropy
> || perhaps
> |
> | I tried anistropy, but the groove pattern didn't show up very well
> | with that technique.  It pretty much just looked like a flat disc
> | with an eliptical highlight on it, not really what I want.  The
> | highlight should be wider towards the edges of the disc and narrower
> | in the middle.
> |
> | Quick Google search example:
> | http://www.veryComputer.com/
> |
> | Not exactly the effect I'm going for, but closer than anything I've
> | gotten.  I'm surprised a simple grooved bump map isn't enough in this
> | case...

> bump mapping would work, but the amount of AA required would make it a
> * to render quickly.. or pretty high AA and a much larger image to
> scale down aswell as anisotropy

> have you tried scanning an LP, never tried it but it might get a more
> realistic bump pattern out of it and not need as much AA to smooth it out
> perhaps?

> keep trying though, your on the right track

Took a look at that image...  and realized the only way I'd be able to do
that right now would involve some pretty complex lighting (even worse if I
had to animate it in anything but a linear or radial fashion).  What... is
ansiotropy?

It's complex as hell, but I've also had a little luck by taking two grooved
discs, imbedded in eachother very very slightly offset (so the actual
object's surface that you see inside a groove varies with your angle).  It's
slightly ghettoish, but best attempt I could make on short notice once.

I know what ansiotropy is in lighting and measurement, but I never heard of
it in max.  Is it a built-in function or a seperate plugin?  I have
something similar I want to do (involving the Pioneer and Voyager probes),
so I'm a little eager to duplicate that effect in any way I can.

 
 
 

Vinyl Record

Post by Darrel Hoffma » Thu, 26 Jun 2003 00:19:19


Quote:> Took a look at that image...  and realized the only way I'd be able to do
> that right now would involve some pretty complex lighting (even worse if I
> had to animate it in anything but a linear or radial fashion).

At least I know it's not just me.  It never ceases to amaze me how something that seems so common-place could actually be a real
* of an effect to reproduce in CG.  (I once spent a long time trying to figure out how one would animate the spreading of chunky
peanut butter on soft bread with a serated knife in CG...  That's actually REALLY complicated...)

Quote:>What... is ansiotropy?

Near as I understand it, it gives a distortion to the highlight on an object, so instead of a circular glint on a sphere, you'd have
an elipse.  It works well on things like * tires and liquid goo.  (Somebody once asked for a way to make a honey texture, and
the answer I gave them involved anistropy.)  I don't really have a clear understanding on it other than from a trial-and-error
perspective.  I try it out.  If it looks better, I keep it.  That's about as far as I go.

Quote:> It's complex as hell, but I've also had a little luck by taking two grooved
> discs, imbedded in eachother very very slightly offset (so the actual
> object's surface that you see inside a groove varies with your angle).  It's
> slightly ghettoish, but best attempt I could make on short notice once.

Hmm...  I might try something like that...

Quote:> I know what ansiotropy is in lighting and measurement, but I never heard of
> it in max.  Is it a built-in function or a seperate plugin?  I have
> something similar I want to do (involving the Pioneer and Voyager probes),
> so I'm a little eager to duplicate that effect in any way I can.

It's built in at least in Max 4, and I think it was in 3 as well.  Go to the drop-down where it says "Blinn" by default.  Anistropic
is one of the shaders on the list.
 
 
 

Vinyl Record

Post by Arkla » Thu, 26 Jun 2003 04:11:15


*holds head in pain at the thought of the peanut butter*


Quote:> > Took a look at that image...  and realized the only way I'd be able to
do
> > that right now would involve some pretty complex lighting (even worse if
I
> > had to animate it in anything but a linear or radial fashion).

> At least I know it's not just me.  It never ceases to amaze me how

something that seems so common-place could actually be a real
Quote:> * of an effect to reproduce in CG.  (I once spent a long time trying

to figure out how one would animate the spreading of chunky
Quote:> peanut butter on soft bread with a serated knife in CG...  That's actually

REALLY complicated...)
Quote:

> >What... is ansiotropy?

> Near as I understand it, it gives a distortion to the highlight on an

object, so instead of a circular glint on a sphere, you'd have
Quote:> an elipse.  It works well on things like * tires and liquid goo.

(Somebody once asked for a way to make a honey texture, and
Quote:> the answer I gave them involved anistropy.)  I don't really have a clear

understanding on it other than from a trial-and-error
Quote:> perspective.  I try it out.  If it looks better, I keep it.  That's about
as far as I go.

> > It's complex as hell, but I've also had a little luck by taking two
grooved
> > discs, imbedded in eachother very very slightly offset (so the actual
> > object's surface that you see inside a groove varies with your angle).
It's
> > slightly ghettoish, but best attempt I could make on short notice once.

> Hmm...  I might try something like that...

> > I know what ansiotropy is in lighting and measurement, but I never heard
of
> > it in max.  Is it a built-in function or a seperate plugin?  I have
> > something similar I want to do (involving the Pioneer and Voyager
probes),
> > so I'm a little eager to duplicate that effect in any way I can.

> It's built in at least in Max 4, and I think it was in 3 as well.  Go to

the drop-down where it says "Blinn" by default.  Anistropic

- Show quoted text -

Quote:> is one of the shaders on the list.

 
 
 

Vinyl Record

Post by Darrel Hoffma » Thu, 26 Jun 2003 04:38:58


Quote:> >(I once spent a long time trying to figure out how one would animate the spreading of chunky
> > peanut butter on soft bread with a serated knife in CG...  That's actually REALLY complicated...)

> *holds head in pain at the thought of the peanut butter*

Exactly.  I think even the major huge-budget production houses would just give up and say "Here's 5 bucks.  Go buy some peanut
butter and a loaf of bread."  It's one of those effects that's so complicated it's hardly worth even TRYing to simulate, so you
might as well just use the real thing...
 
 
 

Vinyl Record

Post by Brizo » Thu, 26 Jun 2003 08:58:21


||| (I once spent a long time trying to figure out how one would
||| animate the spreading of chunky
||| peanut butter on soft bread with a serated knife in CG...  That's
||| actually REALLY complicated...)
||
|| *holds head in pain at the thought of the peanut butter*
|
| Exactly.  I think even the major huge-budget production houses would
| just give up and say "Here's 5 bucks.  Go buy some peanut butter and
| a loaf of bread."  It's one of those effects that's so complicated
| it's hardly worth even TRYing to simulate, so you might as well just
| use the real thing...

Would make an interesting challenge no? :)