Ogre iphone shaders

[goshua]

hi all,

i am wondering if this is possible to use ogre shaders to deport to gpu some image processing algorithms on an iphone
looks like it is possible : http://www.ogre3d.org/tikiwiki/Orange+S ... e=Cookbook
but i am looking for portable shaders, and it seems that we can use CG and HLSL shaders with ogre
i would like to know if i can then use GLSL shaders since HLSL should be compatible with on a iphone by using ogre 3D

[masterfalcon]

Absolutely, but the GLES 2 rendersystem is only in the 1.8 branch.

[goshua]

shaders are only available with GLES 2 or i can use SDK1.7.2 to program shaders ? or is this rather a question of shaders language version ?

[masterfalcon]

Ogre 1.7 does not include the GL ES 2 rendersystem. GL ES 1 doesn't support shaders.

[goshua]

switching to 1.8 then
ty

[goshua]

since am running ogre 1.8 on iphone now, i just tried to apply a basic shader i found there :
http://www.ogre3d.org/tikiwiki/Orange+S ... escription
to the demo robot i display
so i added orangeshader.cg & orangeshader.material to my resource path and tried to apply the shader with the following line :

Code: Select all

m_poEntity = m_poSceneManager->createEntity( "Robot", "robot.mesh" );
m_poEntity->setMaterialName( "shader/orange" );

but it generates a crash and log tells me that :

Code: Select all

WARNING: material shader/orange has no supportable Techniques and will be blank. Explanation: 
Pass 0: Fragment program shader/orangeFP cannot be used - not supported.

is it due to the shader format & i should try another shader language instead ?

[masterfalcon]

Cg is not supported, yet. You'll have to go with GLSL ES for now.

[DanielSefton]

Cg is not supported, yet. You'll have to go with GLSL ES for now.

I thought Assaf recently added support for it? Or is that not working on iPhone yet?

[masterfalcon]

It's not entirely working yet.

[goshua]

i am trying so to run the glsl version of that shader, sorry if this is very basic btu this is my first experience with shaders
so i still use :

Code: Select all

m_poEntity = m_poSceneManager->createEntity( "Robot", "robot.mesh" );
m_poEntity->setMaterialName( "shader/orange" );

with the 2 following files :

- orangeshader.material :

Code: Select all

fragment_program shader/orangeFP glsles
 {
     source orangeshader.glsles
 }
 
 material shader/orange
 {
     technique
     {
         pass
         {
             fragment_program_ref shader/orangeFP
             {
             }
             texture_unit
             {
             }
         }
     }
 }

- orangeshader.glsles :

Code: Select all

 void main()
 {
     gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
 }

code crashes at launch
app seems to parse the shader from log :"Parsing script orangeshader.material"
but debugger tells me :

Code: Select all

#0	0x00570f18 in Ogre::GLSLESLinkProgram::compileAndLink at iostream:77

any idea why it is crashing ?

[masterfalcon]

Hmm. It definitely shouldn't crash, regardless of the compilation status. Try adding "profiles glsles" to your program definition. We'll see if that helps.

[goshua]

doesn't help to add "profiles glsles" :

Code: Select all

fragment_program shader/orangeFP glsles
 {
     source orangeshader.glsles
     profiles glsles
 }
 
 material shader/orange
 {
     technique
     {
         pass
         {
             fragment_program_ref shader/orangeFP
             {
             }
             texture_unit
             {
             }
         }
     }
 }

[masterfalcon]

I haven't had coffee yet, but there's also some stuff missing that GLSL ES is more picky about than it's desktop cousin. Namely, version and precision defaults.

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#version 100

precision mediump int;
precision mediump float;

[goshua]

i modified orangeshader.glsles that way :

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#version 100

precision mediump int;
precision mediump float;

void main()
{
	gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}

but still crashes * scratching head *

[masterfalcon]

Oh, here we go. Another difference between desktop and mobile GLSL is that programs must have one vertex and one fragment shader attached, no more, no less. If you add a trivial vertex shader in there as well, that should(hopefully) take care of the crash.

[goshua]

great doesn't crash anymore, ty

still my 3d "shadered" object doesn't appear anymore, and i don't see what the matter is, now this is mostly about shaders programming i guess
i got now 3 files :

- orangeshader.material

Code: Select all

fragment_program shader/orangeFP glsles
 {
     source orangeFragmentShader.glsles
     profiles glsles
 }
 
 vertex_program shader/orangeVP glsles
 {
     source orangeVertexShader.glsles
     profiles glsles
 }
 
 material shader/orange
 {
     technique
     {
         pass
         {
             fragment_program_ref shader/orangeFP
             {
             }
             
             vertex_program_ref shader/orangeVP
             {
             }
         }
     }
 }
 

- orangeFragmentShader.glsles

Code: Select all

#version 100

precision mediump int;
precision mediump float;

void main()
{
	gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}

- orangeVertexShader.glsles

Code: Select all

#version 100

precision mediump int;
precision mediump float;

void main()
{
    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}

[masterfalcon]

Even more fun. Neither gl_ModelViewProjectionMatrix nor gl_Vertex are defined in GLSL ES. You will need to pass them in as uniforms. The sample browser media files should be a good resource for getting some shaders and materials up and running.

[goshua]

yay got a red robot now
ty very much

[meximex]

Hi guys,
any updates on the shaders in iOS?

Is it possible now?

Do you have an idea when 1.8 will come?

[masterfalcon]

No idea on timeline for 1.8 but you can certainly use it. Shaders work great.