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setMaterialUniform
http://horde3d.org/forums/viewtopic.php?f=2&t=832		 Page 1 of 1
Author:  torsk [ 08.07.2009, 08:45 ]
Post subject:  setMaterialUniform
Hello,

I am trying to pass deltatime to my shader in everyframe with setMaterialUniform. I have <Uniform name="time" a="0.1" b="0.1" c="0.1" d="0.1" /> in the material file, and also <Uniform id="time" /> in the beginning of [[FX]] section in my shader.

I try to update "time" with following code:

Code:
...
m_waterMaterial = Horde3D::findResource( ResourceTypes::Material, "models/water/Material__25-material.material.xml" );
...
void GamePlayState::update(float dt)
{
   static float abstime = 0.0f;
   abstime += dt;
   Horde3D::setMaterialUniform(m_waterMaterial, "time", abstime, abstime, abstime, abstime);


Horde3D::setMaterialUniform() returns true, but it doesn't seem to change the uniform vec4 time inside the shader (as nothing changes)...
Any ideas?
Author:  DarkAngel [ 08.07.2009, 09:13 ]
Post subject:  Re: setMaterialUniform
What is the datatype in GLSL? It may need to be a vec4.
Author:  torsk [ 08.07.2009, 09:40 ]
Post subject:  Re: setMaterialUniform
It is.

uniform vec4 time;
Author:  marciano [ 08.07.2009, 20:00 ]
Post subject:  Re: setMaterialUniform
That should definitely work but the problem looks a bit like the one reported here. Unfortunately I could not reproduce it. If you could create a minimal repro case with one of the samples it should be very quick to fix.
Author:  torsk [ 09.07.2009, 08:31 ]
Post subject:  Re: setMaterialUniform
ok, i tried it with the knight sample, and couldn't get it working there either. i am trying to convert ocean shader from rendermonkey samples to horde. here's lines i added to knight Application:init():

Knight Application::init():

Code:
   m_waterMaterial = Horde3D::addResource( ResourceTypes::Material, "models/jokulaatikko/Material__25-material.material.xml", 0 );
   ResHandle waterRes = Horde3D::addResource( ResourceTypes::SceneGraph, "models/jokulaatikko/jokulaatikko.scene.xml", 0 );

   // Load resources
   Horde3DUtils::loadResourcesFromDisk( _contentDir.c_str() );

   NodeHandle waterNode = Horde3D::addNodes( RootNode, waterRes );
   Horde3D::setNodeTransform(waterNode, 30, 0, -20, 0, 0, 0, 1, 1, 1);
        m_counter = 0.0f;


couple of variables to App.h:

Code:
class Application
{
private:

   float            m_counter;
   ResHandle         m_waterMaterial;


Application::mainLoop() :

Code:
void Application::mainLoop( float fps )
{
   Horde3D::setMaterialUniform(m_waterMaterial, "myTime", m_counter, m_counter, m_counter, m_counter);
   m_counter += 1.0f;


and here's link to my relevant shaders/ models/ textures/ :
http://www.drugphish.ch/~thok/monkeywater.rar
Author:  marciano [ 09.07.2009, 19:44 ]
Post subject:  Re: setMaterialUniform
Thanks for the repro case, it helped to find the problem. The bug is very easy to fix; in Renderer::setMaterialRec (Renderer.cpp), modify the line after the comment:
Code:
// Use default values if not found
if( !found && firstRec )
Author:  torsk [ 10.07.2009, 10:23 ]
Post subject:  Re: setMaterialUniform
yaya, thanks for the quick fix :)

btw it would be a good idea to include some kind of a frametimer to horde default shader attributes because so many effects require it.
Author:  marciano [ 11.07.2009, 09:20 ]
Post subject:  Re: setMaterialUniform
torsk wrote:
btw it would be a good idea to include some kind of a frametimer to horde default shader attributes because so many effects require it.

Yes that would be practical. On the other hand Horde does not really have the concept of a global game time. Animation and particles are advanced manually. However, we could add a time parameter to the render function which will just be used as shader uniform.
Author:  Expandable [ 14.07.2009, 07:00 ]
Post subject:  Re: setMaterialUniform
marciano wrote:
However, we could add a time parameter to the render function which will just be used as shader uniform.


I like that idea.
Author:  swiftcoder [ 14.07.2009, 11:36 ]
Post subject:  Re: setMaterialUniform
marciano wrote:
However, we could add a time parameter to the render function which will just be used as shader uniform.
I am not sure global time is a very useful concept in a game renderer - I often need many different timers, so manual uniform upload is better. Also, Horde might be used in contexts where frame-time would be very tricky to determine (i.e. lazy update in a GUI context).
Author:  DarkAngel [ 15.07.2009, 00:23 ]
Post subject:  Re: setMaterialUniform
swiftcoder wrote:
marciano wrote:
However, we could add a time parameter to the render function which will just be used as shader uniform.
I am not sure global time is a very useful concept in a game renderer - I often need many different timers, so manual uniform upload is better. Also, Horde might be used in contexts where frame-time would be very tricky to determine (i.e. lazy update in a GUI context).
I agree.
However, maybe Horde could implement the concept of a "global" uniform? This way the application could set the uniform once, and all materials would receive the value.

This would allow you to easily pass a global timer to all your shaders, but it doesn't directly tie the concept of "time" to Horde ;)
Author:  Siavash [ 15.07.2009, 03:36 ]
Post subject:  Re: setMaterialUniform
Good idea
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