Emitters + Framework

[Quan]

I have been playing around with loading scenes and working out how to use the framework when I ran into a problem with Emitters which I haven't been able to nut out.

 

While loading a scene, I thought ' hey this would be cool with snow ' So I wipped up a emitter in a basic program then moved it into the scene loader.

 

When I compile and run I first get a dialog box with just 0 in it. Then I get Unhanded Exception:Attempt to access field or method of null object. The debugger then points to fw.render()

 

Any ideas as to what I am doing wrong with the Emitters ?

 

Thanks

 

Here is the code for the scene loader:

 

Strict
Framework leadwerks.engine 

Import "C:\Program Files\Leadwerks Engine SDK\BMX\Framework\framework.bmx"
Include "lua-gluefunctions.bmx"

AppTitle:String = "Test World"

RegisterAbstractPath("C:\Program Files\Leadwerks Engine SDK\")

Graphics 1024,768,0

AFilter(1)
TFilter(1)

Global fw:TFramework = TFramework.Create()
If Not fw RuntimeError "Failed to initialize engine."

       SetScriptObject("fw", fw)'Setup the global script objects.
       SetPostFX()'Setup the post processing FX

Local cam:TCamera = fw.Main.Camera
MoveEntity cam, Vec3(0, 20, - 3)
TurnEntity cam, Vec3(5, 0, 0)

local scene:TEntity = LoadScene("abstract::basic.sbx")

local snowemitter:TEmitter=CreateEmitter(100,1000)
PaintEntity snowemitter,LoadMaterial("Abstract::dust.mat")
SetEmitterRadius snowemitter,0,0.1
SetEmitterArea snowemitter,vec3(100)
SetEmitterVelocity snowemitter,vec3(0),vec3(1)
SetEmitterAcceleration snowemitter,vec3(0,-0.5,0)
SetEmitterWaver snowemitter,2.0

'Local music:TSound = LoadSound("C:\BlitzMax\My Projects\LeadWerks Test\Sound\snowing.ogg")
'Global bgmusic:TSource = CreateSource(music,SOURCE_LOOP)
'PlaySource(bgmusic)

Local camrotation:TVec3=Vec3(0) 
Local mx:Float 
Local my:Float 

Local move:Float
Local strafe:Float

HideMouse 
MoveMouse GraphicsWidth()/2,GraphicsHeight()/2

While Not ( KeyHit (KEY_ESCAPE) )

	mx=Curve(MouseX()-GraphicsWidth()/2,mx,6)
	my=Curve(MouseY()-GraphicsHeight()/2,my,6) 
	MoveMouse GraphicsWidth()/2,GraphicsHeight()/2

	camrotation.x=camrotation.x+my/10 
	camrotation.y=camrotation.y-mx/10 
	RotateEntity cam,camrotation

	move =Curve(KeyDown(KEY_W)-KeyDown(KEY_S),move,20) 
	strafe =Curve(KeyDown(KEY_D)-KeyDown(KEY_A),strafe,20) 
	MoveEntity cam,Vec3(strafe/10,0,move/10)

	fw.Update()
	fw.render()
	Flip
Wend

'Functions from Marleys Ghost simple scene loader http://leadwerks.com/werkspace/index.php?/topic/670-a-simple-scene-loader-in-blitzmax/ 

Function SetPostFX()'0 = off : 1 = on.
       fw.renderer.SetAntialias(1)
       fw.renderer.SetBloom(1) 
       fw.renderer.SetGodRays(1)
       fw.renderer.SetHDR(1)
       fw.renderer.SetSSAO(0)
       fw.renderer.SetWireFrame(0)     
End Function

Function SetScriptObject(name:String, o:Object)
       Local size:Int=GetStackSize()
       lua_pushbmaxobject(luastate.L,o)
       lua_setglobal(luastate.L,name)
       SetStackSize(size)
EndFunction

Function GetStackSize:Int()
       Return lua_gettop(luastate.L)
EndFunction

Function SetStackSize(size:Int)
       Local currentsize:Int=GetStackSize()
       If size<currentsize
       lua_pop(luastate.L,currentsize-size)
       EndIf
EndFunction

[macklebee]

you are not alone... even a simple emitter entity placed into an Editor scene and then loaded into a bmax program causes a crash now. I assume it has to do with this statement from Josh's blog:

In addition, particle emitters will now store the particle velocity in the first texture coordinate array of the surface

whatever that means

[Quan]

Well it seems to work if I remove the lua scripts folder from my application folder:

 

 

But then no water or sky but its a start.

[Marleys Ghost]

I added an emitter to the test scene I use with the basic scene loader in Bmax and got the same error .. however I did not get the error when using the same scene with the basic scene loader in C++, and an emitter was placed and working.

[Marleys Ghost]

You have to have the scripts folder in the appdir so removal is not good lol, but intersting you then get an emitter to work after doing so...

[macklebee]

You have to have the scripts folder in the appdir so removal is not good lol, but intersting you then get an emitter to work after doing so...

 

well i assume that shows there's an issue between lua's framework and bmax framework then? something that would affect emitters?

[Marleys Ghost]

Not sure yet, just trying a few things.

[macklebee]

well this is interesting... wh1sper had reported the same bug for c++ on the 6th inside the tracker. but you said it works now for you in c++? did this just get fixed on the c++ side?

[Marleys Ghost]

well this is interesting... wh1sper had reported the same bug for c++ on the 6th inside the tracker. but you said it works now for you in c++? did this just get fixed on the c++ side?

 

 

Just checking on that.. I simply ran the app as was .. need to check the C++ app with the latest scripts and DLL's ..

 

still far too early for problem solving lol

[Marleys Ghost]

ok updated the scripts, DLL's and shader.pak for the C++ app and it still runs fine. Hey god rays has a nice effect on the snow lol ..

[Marleys Ghost]

Extra things tried so far.

 

Regenerated lua-gluefunctions.bmx

Sync'd again (just in case)

Updated the scripts in the appdir

updated DLL's in appdir

 

still getting Unhandled Exception:Attempt to access field or method of null object @ fw.render()

[macklebee]

i get the same error message but nothing that points to fw.render()... the debug option in blide points to josh's emitter.bmx...

[Marleys Ghost]

in the standard Bmax IDE it halts and highlights fw.render() ..

[Quan]

Been doing a bit more testing. It only gets upset if I load a scene with a directional light in it. As soon as I delete that light its happy but I guess that light is what creates the godrays.

 

As a test I added a directional light to my test code with no scene and I got the same issue. Removed Emitters and the program compiles ( and I now have godrays ).

[Marleys Ghost]

yeah you need the D-Light for G-Rays ... the same scene I am using that gets the issue in Bmax works fine in C++ the scene only has the one light, a D-Light ..

[Quan]

Sitting down last night I dragged out the C++ compiler and did a bit more testing.

 

What I found is I get the same sort of crash when I run this C++ code. If you change from a Directional Light to a point light it is fine.

 

//	====================================================================
//	This file was generated by Leadwerks C++/LEO/BlitzMax Project Wizard
//	Written by Rimfrost Software
//	http://www.rimfrost.com 
//	====================================================================

#include "engine.h"

int WINAPI WinMain( HINSTANCE hInstance,
				HINSTANCE hPrevInstance,
				LPSTR lpCmdLine,
				int nShowCmd ) 
{
Initialize() ;
RegisterAbstractPath("C:/Program Files/Leadwerks Engine SDK");
SetAppTitle( "LWVS2008test" ) ;
Graphics( 1024, 768 ) ;
AFilter() ;
TFilter() ;

TWorld	world;
TBuffer gbuffer;

world = CreateWorld() ;
if (!world) {
	MessageBoxA(0,"Error","Failed to create world.",0);
	return Terminate();
}

gbuffer=CreateBuffer(GraphicsWidth(),GraphicsHeight(),BUFFER_COLOR|BUFFER_DEPTH|BUFFER_NORMAL);

TEntity cam;
cam=CreateCamera(0);
MoveEntity(cam,Vec3(0,0,-5));

TMesh cube;
cube=CreateCube(0);
MoveEntity(cube,Vec3(1,0,0));

TMesh ground;
ground=CreateCube(0);
ScaleEntity(ground,Vec3(50,.1,50));
MoveEntity(ground,Vec3(0,-20,0));

TLight light=CreateDirectionalLight(); // causes crash.
// TLight light=CreatePointLight(); // works fine.
PositionEntity(light,Vec3(2,2,-2));
RotateEntity(light,Vec3(45,45,0));
SetShadowmapSize(light,512);

TEmitter snowemitter = CreateEmitter(500,10000);
PaintEntity (snowemitter,LoadMaterial("Abstract::dust.mat"));
SetEmitterRadius (snowemitter,0,0.2);
SetEmitterArea (snowemitter,Vec3(100));
SetEmitterVelocity (snowemitter,Vec3(0),Vec3(1));
SetEmitterAcceleration (snowemitter,Vec3(0,-0.5,0));
SetEmitterWaver (snowemitter,2.0);

EntityParent(snowemitter,cam);


// Game loop
while( !KeyHit() && !AppTerminate() )
{
		TurnEntity(cube,Vec3(1,1,0));
		UpdateWorld(1);
		SetBuffer(gbuffer);
		RenderWorld(RENDER_ALL);
		SetBuffer(BackBuffer());
		RenderLights(gbuffer);
		Flip(1) ;

}

// Done
return Terminate() ;
}

[Marleys Ghost]

I think theres more to this than just the emitters

[macklebee]

yeah, this looks like there are some files that didn't get updated for this update...

 

so far:

• Emitters (whether created by bmax or loaded from a sbx) will crash the bmax program with blide pointing at an issue at Emitters.bmx (maxide points to the fw.Render())
  
• Any pointlight in a scene with water loaded into a bmax program will crash the program with blide pointing to world.bmx (maxide points to the fw.Render())
  

[Quan]

Yep.

 

Now that I can see the snow I have noticed that its falling behind the water. I think this is because its on the wrong layer but I am not sure how to tell the emitter to be in the transparency layer.

 

When it comes to using the framework I do get a bit lost

[macklebee]

SetWorld(fw.transparency.world)
then create the emitter
and set its properties
...
SetWorld(fw.main.world)

 

But there is a bigger issue happening here. Any emitter created and saved in an Editor scene will crash a bmax program. Same thing happens with pointlights and waterplanes. Both emitters and pointlights were worked on during this update. So I am hoping Josh just forgot to upload some new files...

[Marleys Ghost]

Certainly something is broken thats for sure ..

 

As mack said about the Waterplane and pointlight .. a simple scene with only a water plane and a PLight will cause the error .. other scenes when a P light is rendered and its light would fall "onto" a WPlane .. the error happens. I have checked the same scenes in C++ and no error. The same for emitters .. any scene with an emitter causes the crash, not so in C++ as far as I can tell.

[Marleys Ghost]

Yep seems something is broken in 2.31

[Marleys Ghost]

actually it seems it happens if the P-Light is rendered in the same view as the WPlane it does not have to actually render on it

[macklebee]

yes. it only crashes once you try to render a pointlight and a waterplane at the same time.

[Marleys Ghost]

 

The Emitter Problem:

 

Basic scene, 1 x Directional light : 1 x Skybox : 1 x Terrain : 1 x Emitter (all generic to the SDK)

 

LE_TEST.zip

 

Using the Basic Scene Loader code it will crash the app with:

 

"Unhandled Exception:Attempt to access field or method of null object."

 

The debugger then points to fw.render()

 

Remove the Emitter and alls well in the world. Except of course no emitter