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looking for glsl examples with multiple textures

August 30, 2006 | 1:10 pm

hello,
i’d like to have access to multiple textures inside the fragment progarm of my glsl script. i’m looking at things like the compositing examples with jit.gl.slab and i see that the two textures enter the object from its two inlets, and within glsl are refered to using

// texcoords
varying vec2 texcoord0;
varying vec2 texcoord1;

// samplers
uniform sampler2DRect tex0;
uniform sampler2DRect tex1;

what i would like to do is apply a shader to a thing i’m rending with jit.gl.mesh; what i’m not sure about is how to access the textures and how they will be numbered. my intuition is, if i want two videos as textures, i use two jit.qt.movie’s and two jit.gl.textures and name them differently, and then tell jit.gl.mesh "textures mytext1 mytext2". but i can’t find any examples that make user of multiple textures, in jitter, without jit.gl.slab.

would someone be able to point me to some existing patches?

thank you,
a


August 30, 2006 | 3:48 pm

@texture tex0 tex1 will work. The order you specify textures in will
correspond to the texture integer number. For instance if I have this
at the top of my shader:

, it will be the first
texture in the list. If I have this:

it will be the second
texture in the list.

wes

On 8/30/06, Ali Momeni wrote:
>
>
>
> hello,
> i’d like to have access to multiple textures inside the fragment progarm of my glsl script. i’m looking at things like the compositing examples with jit.gl.slab and i see that the two textures enter the object from its two inlets, and within glsl are refered to using
>
> // texcoords
> varying vec2 texcoord0;
> varying vec2 texcoord1;
>
> // samplers
> uniform sampler2DRect tex0;
> uniform sampler2DRect tex1;
>
>
> what i would like to do is apply a shader to a thing i’m rending with jit.gl.mesh; what i’m not sure about is how to access the textures and how they will be numbered. my intuition is, if i want two videos as textures, i use two jit.qt.movie’s and two jit.gl.textures and name them differently, and then tell jit.gl.mesh "textures mytext1 mytext2". but i can’t find any examples that make user of multiple textures, in jitter, without jit.gl.slab.
>
> would someone be able to point me to some existing patches?
>
> thank you,
> a
>
>
>


August 30, 2006 | 4:13 pm

In the Jitter Tutorials, there is a 4-input compositing example using
jit.gl.slab. I recommend having a look at the accompanying shader.

Andrew


August 30, 2006 | 4:28 pm

yes yes, i’m aware of that one; i was wondering if there are any examples of shaders applied to an object creating geometries like a jit.gl.gridshape or a jit.gl.mesh or somethin, and then a fragment shader that uses multiple textures from jitter.

but along with what i tested and what wes pointed out, i just tried it out and it looks like it works just fine with my shader applied to a jit.gl.mesh geometry. i have access to multiple textures as long as i have multiple named jit.gl.textures and i send a "texture tex1 tex2…" message to jit.gl.mesh. excellent; it’s all very exciting this shader business; one can do real-time video on an apple computer after all.


August 30, 2006 | 4:32 pm

Don’t overlook the math (op.*.jxs), composite (co.*.jxs), and
transition (tn.*.jxs) shaders…

-Joshua


August 30, 2006 | 4:35 pm

On Aug 30, 2006, at 9:28 AM, Ali Momeni wrote:

> yes yes, i’m aware of that one; i was wondering if there are any
> examples of shaders applied to an object creating geometries like a
> jit.gl.gridshape or a jit.gl.mesh or somethin, and then a fragment
> shader that uses multiple textures from jitter.

Nothing about these shaders that are slab specific. You can apply a
shader to any geometry (slab just has some special viewport aligned
geometry rendering to its own context), and then just use a
multitexture texture attribute. These slab focused shaders just don’t
do some of the common things like lighting calculations, but you can
add that in if you like.

-Joshua


August 30, 2006 | 4:42 pm

> one can do real-time video on an apple computer after all.
>

More than that, one can do HD compositing on an apple with quite a
number of filters applied.

wes


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