This one implements the Tranguloid Trefoil equation:

http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip

wes

I just picked up the Orange Book today, its been super helpful
already. Ive been able to properly antialias some of the procedural
texture generators ive made.

Might be interesting to put in two formulas and add mix() to morph
between vertex targets. Hmmm :)

On Sep 13, 2007, at 9:39 PM, Wesley Smith wrote:

> Hi folks,
> Here’s a shader and patch I made following the “Calculate Normals In
> Shader” blog entry on http://tonfilm.blogspot.com/ . It should be
> quite easy to plug in other equations from
> http://local.wasp.uwa.edu.au/%7Epbourke/surfaces_curves/ .
>
> This one implements the Tranguloid Trefoil equation:
> http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip
>
>
> wes

v a d e //

http://www.vade.info
abstrakt.vade.info

wes

On 9/13/07, vade wrote:
> Nice one :)
>
> I just picked up the Orange Book today, its been super helpful already. Ive
> been able to properly antialias some of the procedural texture generators
> ive made.
>
> Might be interesting to put in two formulas and add mix() to morph between
> vertex targets. Hmmm :)
>
>
> On Sep 13, 2007, at 9:39 PM, Wesley Smith wrote:
>
> Hi folks,
> Here’s a shader and patch I made following the “Calculate Normals In
> Shader” blog entry on http://tonfilm.blogspot.com/ . It should be
> quite easy to plug in other equations from
> http://local.wasp.uwa.edu.au/%7Epbourke/surfaces_curves/ .
>
> This one implements the Tranguloid Trefoil equation:
> http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip
>
>
> wes
>
> v a d e //
>
> http://www.vade.info
> abstrakt.vade.info
>
>
>
>
>
>

so you have shader “A” which has 1,2, shader b has 2 and 3, shader
c forumals 3 and 4

when you go from 1 to 2, you can then switch to shader b, go form 2
to 3, then to shader c which has 3 to 4 ?

I dunno, does having the shader uploaded but not bound waste GPU
cycles? I dont think so right?

Might be a solution :)

Either way, very cool.

AB

wes

On Sep 13, 2007, at 9:39 PM, Wesley Smith wrote:

> Hi folks,
> Here’s a shader and patch I made following the “Calculate Normals In
> Shader” blog entry on http://tonfilm.blogspot.com/ . It should be
> quite easy to plug in other equations from
> http://local.wasp.uwa.edu.au/%7Epbourke/surfaces_curves/ .
>
> This one implements the Tranguloid Trefoil equation:
> http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip
>
>
> wes
>

wes

On 9/13/07, joshua goldberg wrote:
> this looks cool, but i’m shocked and saddened about how slow it is on
> my 1.67g4 albook. is that a surprise? it feels like 5fps.
>
>
> On Sep 13, 2007, at 9:39 PM, Wesley Smith wrote:
>
> > Hi folks,
> > Here’s a shader and patch I made following the “Calculate Normals In
> > Shader” blog entry on http://tonfilm.blogspot.com/ . It should be
> > quite easy to plug in other equations from
> > http://local.wasp.uwa.edu.au/%7Epbourke/surfaces_curves/ .
> >
> > This one implements the Tranguloid Trefoil equation:
> > http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip
> >
> >
> > wes
> >
>
>

> this looks cool, but i’m shocked and saddened about how slow it is
> on my 1.67g4 albook. is that a surprise? it feels like 5fps.

v a d e //

http://www.vade.info
abstrakt.vade.info

that

wes

#P window setfont “Sans Serif” 9.;
#P flonum 720 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P window linecount 1;
#P message 720 247 59 196617 param6 $1;
#P flonum 658 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 658 247 59 196617 param5 $1;
#P flonum 596 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 596 247 59 196617 param4 $1;
#P flonum 534 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 534 247 59 196617 param3 $1;
#P flonum 472 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 472 247 59 196617 param2 $1;
#P flonum 410 227 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 410 247 59 196617 param1 $1;
#P flonum 348 228 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 348 248 59 196617 param0 $1;
#P newex 416 304 76 196617 prepend param;
#P flonum 329 284 70 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 329 303 78 196617 param delta $1;
#P message 223 303 82 196617 file vd.math.jxs;
#P newex 223 333 240 196617 jit.gl.shader test @file vd.math.jxs @name surface;
#P button 107 196 15 0;
#P newex 107 268 157 196617 jit.gl.mesh test @shader surface;
#P newex 107 218 142 196617 jit.matrix 3 float32 100 100;
#P newex 107 240 196 196617 jit.expr @expr “norm[0]” “norm[1]” “0″;
#P message 158 81 34 196617 reset;
#P newex 158 101 186 196617 jit.gl.handle test @inherit_transform 1;
#P newex 23 101 48 196617 r render;
#P toggle 138 72 15 0;
#N vpatcher 53 128 279 297;
#P inlet 106 30 15 0;
#P window setfont “Sans Serif” 9.;
#P window linecount 0;
#P newex 43 95 47 196617 gate 1 1;
#P newex 42 116 41 196617 s draw;
#P window linecount 1;
#P newex 17 52 58 196617 t b b erase;
#P inlet 17 32 15 0;
#P outlet 17 83 15 0;
#P connect 1 0 2 0;
#P fasten 2 2 0 0 70 75 22 75;
#P connect 2 0 0 0;
#P connect 4 0 3 0;
#P fasten 5 0 4 0 111 88 48 88;
#P fasten 2 1 4 1 46 83 85 83;
#P lcolor 15;
#P pop;
#P newobj 76 101 42 196617 p Draw;
#P toggle 214 40 15 0;
#P message 214 60 68 196617 fullscreen $1;
#N vpatcher 30 89 166 253;
#P window setfont “Sans Serif” 9.;
#P newex 50 71 35 196617 sel 27;
#P newex 50 50 40 196617 key;
#P outlet 50 93 15 0;
#P connect 1 0 2 0;
#P connect 2 0 0 0;
#P pop;
#P newobj 231 40 33 196617 p Esc;
#P newex 214 78 151 196617 jit.window test @depthbuffer 1;
#P toggle 76 53 15 0;
#P newex 76 72 57 196617 qmetro 30;
#P newex 76 128 187 196617 jit.gl.render test @erase_color 0 0 0 1;
#P connect 33 0 20 0;
#P connect 31 0 20 0;
#P connect 29 0 20 0;
#P connect 27 0 20 0;
#P connect 25 0 20 0;
#P connect 23 0 20 0;
#P connect 21 0 20 0;
#P connect 34 0 33 0;
#P connect 32 0 31 0;
#P connect 30 0 29 0;
#P connect 28 0 27 0;
#P connect 26 0 25 0;
#P connect 24 0 23 0;
#P connect 22 0 21 0;
#P fasten 20 0 16 0 421 325 228 325;
#P connect 13 0 12 0;
#P connect 12 0 14 0;
#P connect 19 0 18 0;
#P connect 17 0 16 0;
#P fasten 18 0 16 0 334 321 228 321;
#P connect 5 0 3 0;
#P connect 6 0 5 0;
#P connect 4 0 6 0;
#P connect 11 0 10 0;
#P fasten 8 0 7 1 143 94 113 94;
#P connect 15 0 13 0;
#P fasten 10 0 0 0 163 123 81 123;
#P connect 7 0 0 0;
#P fasten 9 0 0 0 28 123 81 123;
#P connect 1 0 7 0;
#P connect 2 0 1 0;
#P window clipboard copycount 35;

////////////////////////////////////////////////////////////////Shader

Shader Phong per-pixel lighting in GLSL

I’m not usually a big supporter of mathematical surfaces, but I guess
I’m beginning to see the light.

Happy Patching!

Andrew B.

AB

Max 4.6.3 Jitter 1.6.3
1.67 Ghz Powerbook G4
OS 10.4.10

May just be my problem,
Keith

On 9/14/07, Andrew Benson wrote:
> oops, that patch had a minor issue. This one will work better.
>
> AB
>
>
>
>

AB

That helped with the framerate. I was confused by the complete black
jit.window. A little jit.gl.handle and parameter tweaking did the
trick too.

Thanks,
Keith

I have just one issue with it, and that is that the texture params “fig”
and “thresh” control an effect that seems quite jagged – is there a way
to antialias there? That would make it even more awesome.

Andreas.

many thanks to all

If you do want to keep the depthbuffering and need antialiasing, you
could always render to a double-size texture and do averaging
downsamples, as has been discussed previously.

Best,
Andrew B.

AB

Why do all this in a shader, why not use jit.expr to calculate
geometry for surfaces and then the normals? Is there a benefit to
first calculating a normal-distribution-based coordinate spread for a
plane, and then using that as input into a shader?

I have a friend who does a lot of OpenGL programming, and he swears
by using only vertex arrays (especially cached) and standard opengl
blend modes. But he doesn’t know shaders well, I feel like there
could be something he’s missing.

Cheers
Evan

On Sep 14, 2007, at 2:39 AM, Wesley Smith wrote:

> Hi folks,
> Here’s a shader and patch I made following the “Calculate Normals In
> Shader” blog entry on http://tonfilm.blogspot.com/ . It should be
> quite easy to plug in other equations from
> http://local.wasp.uwa.edu.au/%7Epbourke/surfaces_curves/ .
>
> This one implements the Tranguloid Trefoil equation:
> http://www.mat.ucsb.edu/~whsmith/ShaderSurface.zip
>
>
> wes

> Here’s a random question about this… not to provoke an argument,
> but simply because I’m always curious about the “best” way of doing
> anything.

I guess my general practice is to let the system breathe… So stuff
as much as you can on a GPU, until it strats to choke.

> Why do all this in a shader, why not use jit.expr to calculate
> geometry for surfaces and then the normals? Is there a benefit to
> first calculating a normal-distribution-based coordinate spread for
> a plane, and then using that as input into a shader?

It is simple, and since the vertices are sent only once – there’s
almost no performance hit.
Also, as far as I know, shaders are incapable of creating new vertices.

> I have a friend who does a lot of OpenGL programming, and he swears
> by using only vertex arrays (especially cached) and standard opengl
> blend modes. But he doesn’t know shaders well, I feel like there
> could be something he’s missing.

he’s missing a lot! Many of the patches posted lately on the list
would be very hard, if not impossible, to recreate while using only
GPU without the shaders.

just my 0.2RSD

nesa

Imagine doing this:

x = 2 sin(3 u) / (2 + cos(v))
y = 2 (sin(u) + 2 sin(2 u)) / (2 + cos(v + 2 pi / 3))
z = (cos(u) – 2 cos(2 u)) (2 + cos(v)) (2 + cos(v + 2 pi / 3)) / 4

with jit.expr at 30fps on a 50×50 grid. You’re framerate will crawl
if not die if you do it on the CPU. On the GPU you can warp the
coordinate range and other fun stuff dynamically for smooth
animations. jit.gl.mesh does use VBOs under the hood for sending the
planar data so that is also fast.

> It is simple, and since the vertices are sent only once – there’s
> almost no performance hit.
> Also, as far as I know, shaders are incapable of creating new vertices.
>

Not entirely true. With Geometry shaders, you can generate quite a
large number of vertices on the GPU.

>
> > I have a friend who does a lot of OpenGL programming, and he swears
> > by using only vertex arrays (especially cached) and standard opengl
> > blend modes. But he doesn’t know shaders well, I feel like there
> > could be something he’s missing.

VBOs are definnitely best practice for dispatching data to the GPU but
shaders are required for complex rendering effects. Blend modes are
nice but limited. For example, you can’t do per-pixel lighting with
just VBOs and blend modes.

wes

ah yes!(that is too new for my hardware:)

also, how would one do that with jitter?