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Member Since 25 Mar 2010
Offline Last Active Mar 03 2013 06:58 AM

Topics I've Started

Ragdoll wrong transformation matrix ruins skinned mesh

11 December 2010 - 01:52 AM

Its a DirectX matrix question so I thought this section is appropriate. Ok, here is the problem I was about to complete my game but then my mind demanded more so I thought of applying ragdolls in my game:
1. My game uses nVIDIA PhysX engine.
2. Im currently using hardware skinning.
3. I create my ragdoll using box shapes.
4. The ragdoll creation is ok as I have tested it in Visual debugger.
5. After applying ragdoll I get the transforms of each actor and apply it directly to the skinned mesh. So here is the problem. After applying this my mesh is not drawn correctly. I know that you cannot just apply directly the transforms to the bones but here Im totally clueless. Here are the screens:
Ragdoll switched off
Ragdoll on

And here is the code of ragdoll creation:

void peds::CreateRagdoll()
NxQuat qRotLeft, qRotRight, qRotAround;
qRotLeft.fromAngleAxis(90, NxVec3(0,0,1));
qRotRight.fromAngleAxis(-90, NxVec3(0,0,1));
qRotAround.fromAngleAxis(180, NxVec3(0,0,1));


//Get current bone transforms from skinned mesh and make ragdoll actors
//depending upon the transforms
vector<D3DXMATRIX> a = player.pedsMesh.getTransforms();

//Disable character controller collision

///Create Ragdoll Actors////
/Code removed

for(int x=0 ; x< player.pedsMesh.NumBones() ; x++)
NxMat34 b;


//Create Actors
//COde removed

//Transform the ragdoll created to current player position
for(int x=0 ; x<player.pedsMesh.NumBones() ; x++)

D3DXMatrixMultiply(&a[x], &a[x], &player.pedsMesh.wowMatrix);
NxMat34 b;

Code fo getting actor transforms and applying it to skinned mesh:

//Get current player matrix and apply it to world matrix
effect->SetMatrix("world", &player.pedsMesh.wowMatrix);
//Get bone transforms
effect->SetMatrixArray("gFinalXForms", player.pedsMesh.getFinalXFormArray(), player.pedsMesh.NumBones());

effect->SetMatrix("world", &worldMatrix);
//Get actor transforms and apply it to skined mesh
//<-- This is the wrong stuff --->
for(int x=0 ; x<player.pedsMesh.NumBones() ; x++)
// Get actors global pose in world space
D3DXMatrixScaling(&scale, 2.5f, 2.5f, 2.5f);
D3DXMatrixMultiply(&transformation[x], &scale, &transformation[x]);

//effect->SetMatrix("world", &scale);
effect->SetMatrixArray("gFinalXForms", &transformation[0], player.pedsMesh.NumBones());


And here is the most common skinning shader code !

float4x4 world;
float4x4 view;
float4x4 projection;
float3 eyePos;
float4x4 InverseTransposeView;

uniform extern float4x4 gFinalXForms[35];

texture colorMap;
sampler colorMapSampler = sampler_state
Texture = <colorMap>;
MinFilter = Anisotropic;
MagFilter = Linear;
MipFilter = Linear;
MaxAnisotropy = 16;

struct OutputVS
float4 vPos : POSITION0;
float2 vTex0 : TEXCOORD0;
float3 vWorldPos : TEXCOORD1;
float3 vWorldNrm : TEXCOORD2;
float3 eyeVec : TEXCOORD3;
float4 vPos1 : TEXCOORD4;

struct OutputPS
float4 vMaterial : COLOR0;
float4 vWorldNrm : COLOR1;
float4 vWorldPosXY : COLOR2;

OutputVS VS_Lambert(float3 posL : POSITION0,
float3 tangentL : TANGENT0,
float3 binormalL : BINORMAL0,
float3 normalL : NORMAL0,
float2 tex0 : TEXCOORD0,
float4 weight0 : BLENDWEIGHT0,
float4 boneIndex : BLENDINDICES)

OutputVS outVS = (OutputVS)0;

float4 vertex = float4(posL, 1);
float LastWeight = 0.0f;
float4 p = 0.0f;
float4 n = 0.0f;

float BlendWeightsArray[4] = (float[4])weight0;
int4 IndexVector = D3DCOLORtoUBYTE4(boneIndex);
int IndexArray[4] = (int[4])IndexVector;

for(int x=0 ; x<3 ; x++)
LastWeight = LastWeight + BlendWeightsArray[x];
p += BlendWeightsArray[x] * mul(float4(posL, 1.0f), gFinalXForms[IndexArray[x]]);
n += BlendWeightsArray[x] * mul(float4(normalL, 0.0f), gFinalXForms[IndexArray[x]]);


LastWeight = 1.0f - LastWeight;
p += LastWeight * mul(float4(posL, 1.0f), gFinalXForms[IndexArray[3]]);
n += LastWeight * mul(float4(normalL, 0.0f), gFinalXForms[IndexArray[3]]);

// p.w = 1.0f;
//n.w = 0.0f;

n = normalize(n);

float4x4 ViewSpace = mul(world, view);
outVS.vWorldPos = mul(p, ViewSpace);
float3 vWorldPos = mul(p, ViewSpace);
outVS.eyeVec = p.xyz - eyePos;
float4x4 viewProjection = mul(view, projection);
outVS.vPos = mul(float4(outVS.vWorldPos, 1), projection);
outVS.vPos1 = outVS.vPos;
outVS.vTex0 = tex0;

outVS.vWorldNrm = normalize(mul(n, (float3x3) InverseTransposeView));

return outVS;

// Pixel shader.

OutputPS PS_Lambert(OutputVS i) : COLOR
OutputPS o;

float distance1 = distance(i.eyeVec, float3(0, 0, 0));

float4 texColor = tex2D(colorMapSampler, i.vTex0);

distance1 /= 460;

//LOD alpha transition
//clip(texColor - distance1/2);

//clip(texColor.a - 0.2f);

//clip(texColor.a - 0.5f);
o.vMaterial.rgb = texColor * 1.5f;
//o.vMaterial.rgb = float3(0.6f, 0.6f, 0.6f);
o.vMaterial.a = texColor.a;

o.vWorldNrm.xyz = 0.5f * (i.vWorldNrm + 1.0f);
o.vWorldNrm.w = 0.0;

o.vWorldPosXY = float4(i.vWorldPos.xyz, 0);

return o;

What should I do to correctly transform my skinned mesh??

My game doesn't work on other PCs

23 October 2010 - 07:00 AM

Well my problem is that I cannot get my game to work on other PCs (Visual Studio and DXSDK not installed). I have created setup of my game, checked all the dependencies, installed VC++ 2008 Redistributable SP1 on other PC but still no luck. The error message I get(the usual) : "The application failed to initialize because its side-by-side configuration is not correct. Please contact....."

Please help,

Sample Reflective shadow maps

07 October 2010 - 06:06 PM

Recently I got a good frame rate when placing thousands of lights because of your help. Now I want to extend my game to support a simple indirect illumination using reflective shadow maps. I read the paper and I found something that I don't understand. Here are the steps:

1. Render the scene from lights POV and store luminance, position and normals.
2. Render the scene from camera view.
3. Deferred pass:

Sample RSM and place VPLs (point lights spheres) with radius depending upon luminance, position. I don't think I require normals as I am only using point lights.

So here is the problem: how should I sample RSM and place VPLs and then iterate through each VPL for lighting? (volume texture??) Or am I doing something wrong?


[Edited by - ayush3017 on October 8, 2010 2:27:55 AM]

Deferred rendering camera close to point light fps drop

05 October 2010 - 10:35 PM

Hello everyone,
In my game I use deferred rendering. I create bounding box for each point light and then use that box by projecting in 2D and then use scissor test to draw the required area affected by the point lights. Here is the test bench:

No.Of.PointLights | FPS.When.Camera.Far | FPS.When.Camera.Close.To.Light
0 85 85
14 84 28
1200 81 26

As you can see when the camera is near to the point light position the frame rate is too low even if their are less number of lights. What could be the problem?

Shadow draw order problem

19 September 2010 - 07:52 AM

hey, I have fully implemented Parallel split shadow map. But if an object A is over object B and the draw order is A then B then A doesn't cast shadow. However if the objects are interchanged and draw order is kept same then shadows appear. So how to draw objects from back to front?? or am I missing something here?