• Advertisement
Sign in to follow this  

shadow volume problem

This topic is 3876 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

shadow volume demo with noise This is my shadow volume demo programmed by DX9. As you can see, it is not good, there is a lot of black noise on the occluder which really confuse me. Could anyone help me out? Below is my render() function(maybe it is a little long :) ):
void CShadowVolumeApplication::Render()
{
    //setup some variables
	D3DXVECTOR4 EyePos(0.0f, 60.0f, -60.0f, 0.0f);
	D3DXMatrixLookAtLH(&m_ViewMatrix, &(D3DXVECTOR3)EyePos,
		&D3DXVECTOR3(0.0f, 0.0f, 0.0f), &D3DXVECTOR3(0.0f, 1.0f, 0.0f));

	float Time = (float)GetTickCount() / 2000.0f;
	D3DXVECTOR4 LightPos(150.0f * sin(Time), 90.0f, 0.0f, 1.0f);

	D3DXVECTOR4 LightDir = D3DXVECTOR4(0.0f, 0.0f, 0.0f, 0.0f) - LightPos;
	D3DXVec4Normalize(&LightDir, &LightDir);

	D3DXVECTOR4 Ambient(0.0f, 0.0f, 0.0f, 0.0f);
	m_pD3DDevice->SetVertexShaderConstantF(5, (float*)&Ambient, 1);

	D3DXVECTOR4 PushDistance(100.0f, 0.0f, 0.0f, 0.0f);
	m_pD3DDevice->SetVertexShaderConstantF(8, (float*)&PushDistance, 1);

	m_pD3DDevice->SetVertexDeclaration(m_pDeclaration);
	m_pD3DDevice->SetVertexShader(m_pBasicShader);

	//if I comment out this line, the noise will disappear,
    //but as you can expect, stippling effect will occur,
    //but I also think the noise also have something to do with this
	m_pD3DDevice->SetRenderState(D3DRS_DEPTHBIAS, 10);

    //draw the white plane
	RenderPlane();

	//draw the occluder
	D3DXMATRIX Rotation;
	D3DXMATRIX Translation;

	D3DXMatrixTranslation(&m_WorldMatrix, 20.0f, 10.0f, 0.0f);
	D3DXMATRIX ShaderMatrix = m_WorldMatrix * m_ViewMatrix * m_ProjectionMatrix;
	D3DXMatrixTranspose(&ShaderMatrix, &ShaderMatrix);
	m_pD3DDevice->SetVertexShaderConstantF(0, (float*)&ShaderMatrix, 4);

	D3DXMATRIX InverseWorld;
	float Det;
	D3DXMatrixInverse(&InverseWorld, &Det, &m_WorldMatrix);
	D3DXVec4Transform(&LightDir, &LightDir, &InverseWorld);
	D3DXVec4Normalize(&LightDir, &LightDir);
	m_pD3DDevice->SetVertexShaderConstantF(4, (float*)&LightDir, 1);

	D3DXVec4Transform(&LightPos, &LightPos, &InverseWorld);
	m_pD3DDevice->SetVertexShaderConstantF(7, (float*)&LightPos, 1);

	D3DXMatrixRotationY(&Rotation, (float)GetTickCount() / 1000.0f);
	D3DXMatrixTranslation(&Translation, 0.0f, 20.0f, 0.0f);
	m_WorldMatrix = Rotation * Translation;
	
	ShaderMatrix = m_WorldMatrix * m_ViewMatrix * m_ProjectionMatrix;
	D3DXMatrixTranspose(&ShaderMatrix, &ShaderMatrix);
	m_pD3DDevice->SetVertexShaderConstantF(0, (float*)&ShaderMatrix, 4);
	D3DXMatrixInverse(&InverseWorld, &Det, &m_WorldMatrix);
	D3DXVec4Transform(&LightDir, &LightDir, &InverseWorld);
	D3DXVec4Normalize(&LightDir, &LightDir);
	m_pD3DDevice->SetVertexShaderConstantF(4, (float*)&LightDir, 1);
	D3DXVec4Transform(&LightPos, &LightPos, &InverseWorld);
	m_pD3DDevice->SetVertexShaderConstantF(7, (float*)&LightPos, 1);

	m_pD3DDevice->SetStreamSource(0, m_pMeshVertexBuffer, 0, sizeof(MESH_VERTEX));
	m_pD3DDevice->SetIndices(m_pMeshIndexBuffer);
	m_pD3DDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, m_pMesh->GetNumVertices(), 0,
		m_pMesh->GetNumFaces());//end draw of occluder

	//draw shadow volume in stencil buffer
	m_pD3DDevice->Clear(0, NULL, D3DCLEAR_STENCIL, 0, 1.0f, 0);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILENABLE, TRUE);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILFUNC,   D3DCMP_ALWAYS);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILPASS,   D3DSTENCILOP_INCR);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILREF,    1);

	m_pD3DDevice->SetRenderState(D3DRS_ZWRITEENABLE, FALSE);

	m_pD3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, TRUE);
	m_pD3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ZERO);
	m_pD3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);

	m_pD3DDevice->SetVertexShader(m_pVolumeShader);

	m_pD3DDevice->SetRenderState(D3DRS_DEPTHBIAS, 0);

	//two pass:
	m_pD3DDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW);
	m_pD3DDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, m_pMesh->GetNumVertices(), 0,
		m_pMesh->GetNumFaces());

	m_pD3DDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CW);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILPASS, D3DSTENCILOP_DECR);
	m_pD3DDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, m_pMesh->GetNumVertices(), 0,
		m_pMesh->GetNumFaces());//end draw of shadow volume

	//draw the screen rectangle that make the shadow
	m_pD3DDevice->SetRenderState(D3DRS_STENCILFUNC, D3DCMP_LESSEQUAL);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILPASS, D3DSTENCILOP_KEEP);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILREF,  1);

	m_pD3DDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
	m_pD3DDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);
	m_pD3DDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
	m_pD3DDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);


	m_pD3DDevice->SetVertexShader(NULL);
	m_pD3DDevice->SetFVF(D3DFVF_MASKVERTEX);
	m_pD3DDevice->SetStreamSource(0, m_pMaskVertexBuffer, 0, sizeof(MASK_VERTEX));
	m_pD3DDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 0, 2);//end draw of the screen rect

	//switch everythig back
	m_pD3DDevice->SetRenderState(D3DRS_ZENABLE, TRUE);
	m_pD3DDevice->SetRenderState(D3DRS_STENCILENABLE, FALSE);
	m_pD3DDevice->SetRenderState(D3DRS_ZWRITEENABLE, TRUE);
	m_pD3DDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
}


And every frame I will clear out the buffer:
m_pD3DDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER , D3DCOLOR_XRGB(100, 100, 200), 1.0f, 0);

Share this post


Link to post
Share on other sites
Advertisement
Nobody can help? Come on, at least give me some hints :)

Share this post


Link to post
Share on other sites
How are you capping your shadow volume? Front or back faces of the mesh? If front, try capping with the back facing polys - i had similar results as you until i did this (dx8 though).
Hope that helps.
Steele.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement