technique Fog
{
    pass P0
    {
        pixelshader      = null;
        vertexshader     = null;
        FogVertexMode = LINEAR; 
        FogStart      = 50.0f; 
        FogEnd        = 300.0f; 
        FogColor      = 0x00CCCCCC; 
        FogEnable     = false;       
    }
}

Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00CCCCCC, 1.0f, 0);
		Device->BeginScene();

		// set the technique to use
		FogEffect->SetTechnique( FogTechHandle );

		UINT numPasses = 0;
    	FogEffect->Begin(&numPasses, 0);

		D3DXMATRIX I;
		D3DXMatrixIdentity(&I);
		for(int i = 0; i < numPasses; i++)
		{
			FogEffect->BeginPass(i);

			if( TheTerrain )
				TheTerrain->draw(&I, false);
		}
		FogEffect->End();

		if( ::GetAsyncKeyState('F') & 0x8000f )
		{
			Device->SetRenderState(D3DRS_FOGENABLE, true);

			Device->SetRenderState( D3DRS_FOGSTART, 50.0f );
			Device->SetRenderState( D3DRS_FOGEND, 300.0f );
			Device->SetRenderState( D3DRS_FOGCOLOR, 0x00ffCCCC );
			Device->SetRenderState( D3DRS_FOGTABLEMODE ,  D3DFOG_LINEAR);
		}

		Device->EndScene();

		Device->Present(0, 0, 0, 0);

Quote:Original post by MJP
When you call FogEffect->BeginPass(0), the ID3DXEffect interface calls IDirect3DDevice9::SetRenderState and sets the fog states according to what you have in the effect file. This means it will override the render states you're setting later, after you've drawn everything.

You'll have to either...

a) Set the render state after you call BeginPass and before you render your terrain. You'll also have to do it every frame, since every time you call BeginPass the effect will set things as they are in the technique

b) Make 2 techniques, one with fog and one without. Then pick the technique you want based on user input. This, IMO, is more ideal than a).

Quote:Original post by MJP

Quote:Original post by huaner

Quote:Original post by MJP
When you call FogEffect->BeginPass(0), the ID3DXEffect interface calls IDirect3DDevice9::SetRenderState and sets the fog states according to what you have in the effect file. This means it will override the render states you're setting later, after you've drawn everything.

You'll have to either...

a) Set the render state after you call BeginPass and before you render your terrain. You'll also have to do it every frame, since every time you call BeginPass the effect will set things as they are in the technique

b) Make 2 techniques, one with fog and one without. Then pick the technique you want based on user input. This, IMO, is more ideal than a).

if i beginpass at first, will it override the render states later? i found if i disable the fog in the pass, later i enable it by SetRenderState, the somethings i draw out shader is effected by fog.

ID3DXEffect will always set render states in BeginPass. If you're confused about the order in which things are occurring, go ahead and capture a frame in PIX and look at the order in which SetRenderState calls occur.

Quote:
You can control all render states and sampler state settings with parameters (makes it easy to e.g. control texture filtering from the app).

Quote:
pass P0
{
Sampler[0] = (LayerMap0Sampler);
Sampler[1] = (BlendMapSampler);
vertexShader = compile vs_2_0 Terrain_MultiTexVS();
pixelShader = compile ps_2_0 Terrain_MultiTexPS1();


FogEnable = bEnableFog;
FogStart = g_FogStart;
FogEnd = g_FogEnd;
FogColor = g_FogColor;
}

Quote:
//set fog start
D3DXHANDLE FogStartHandle = g_pEffect->GetParameterByName(0, "g_FogStart");
g_pEffect->SetFloat(FogStartHandle, 300.0f);

//set fog end
D3DXHANDLE FogEndHandle = g_pEffect->GetParameterByName(0, "g_FogEnd");
g_pEffect->SetFloat(FogEndHandle, 3000.0f);

//set fog color
D3DXVECTOR4 colorfog = D3DXVECTOR4(1.0f, 1.0f, 1.0f, 1.0f);
D3DXHANDLE FogColorHandle = g_pEffect->GetParameterByName(0, "g_FogColor");
g_pEffect->SetVector(FogColorHandle, &colorfog);

Quote:
// grab a handle to the parameter
D3DXHANDLE enableFogHandle = fx->GetParameterByName("g_enableFog");
// to enable fog
fx->SetBool(enableFogHandle, true);
// to disable fog
fx->SetBool(enableFogHandle, false);

bool fogenable = true;g_pEffect->SetValue("bEnableFog", &fogenable, sizeof(bool));