I'm working with dx12 and hlsl, and this specific root constant seems doesn't change or doesn't work for index.

this is hlsl code

#include "LightUtil.hlsli"

cbuffer cbCameraInfo : register(b1)

{

matrix gmtxViewProj : packoffset(c0);

float3 cameraPos : packoffset(c4);

//size : 19

};

cbuffer cbLightInfo : register(b2)

{

int nLights : packoffset(c0);

int nShadowIndex : packoffset(c4); // - this is the constant

}

cbuffer cbShadowInfo : register(b3)

{

matrix gmtxShadowTransform[3];

matrix gmtxLightViewProj[3];

matrix gmtxCascadedViewProj[3];

float3 ShadowCameraPos;

}

Texture2D gShadowMap[3] : register(t0);

Texture2D gTextureMaps[6] : register(t3);

struct INSTANCED_GAMEOBJECT_INFO

{

matrix m_mtxGameObject;

int m_nTextrueIndex;

};

StructuredBuffer<INSTANCED_GAMEOBJECT_INFO> gGameObjectInfos : register(t0, space1);

StructuredBuffer<LIGHT_INFO> light : register(t1, space1);

SamplerState gsamPointWrap : register(s0);

SamplerState gsamPointClamp : register(s1);

SamplerState gsamLinearWrap : register(s2);

SamplerState gsamLinearClamp : register(s3);

SamplerState gsamAnisotropicWrap : register(s4);

SamplerState gsamAnisotropicClamp : register(s5);

SamplerComparisonState gsamShadow : register(s6);

and when I use nShadowIndex like this

#include "Common.hlsli"

struct VertexIn

{

float3 PosL : POSITION;

};

struct VertexOut

{

float4 PosH : SV_POSITION;

};

VertexOut VS(VertexIn vin)

{

VertexOut vout = (VertexOut) 0.0f;

// Transform to world space.

float4 posW = mul(float4(vin.PosL, 1.0f), gmtxWorld);

// Transform to homogeneous clip space.

vout.PosH = mul(posW, gmtxLightViewProj[nShadowIndex]);

return vout;

}

// This is only used for alpha cut out geometry, so that shadows

// show up correctly. Geometry that does not need to sample a

// texture can use a NULL pixel shader for depth pass.

void PS(VertexOut pin)

{

// Fetch the material data.

MATERIAL matData = material;

float4 diffuseAlbedo = matData.DiffuseAlbedo;

}

this shader always returns same result because of nShadowIndex always fixed to 0.

and this is how i set variables. (there's many other vars, but not that important for this)

as you see, what i'm trying to do is cascaded shadow map.

void CShadowShader::UpdateShaderVariables(ID3D12GraphicsCommandList* pd3dCommandList, XMFLOAT3 xmf3TargetPos, float fBoundary, int nShadowIndex)

{

XMVECTOR lightPos = XMLoadFloat3(&m_pLight->GetPosition());

XMVECTOR TargetPos = XMLoadFloat3(&xmf3TargetPos);

XMVECTOR lightUp = XMLoadFloat3(&m_pLight->GetUp());

XMVECTOR lightDir = XMVectorSubtract(lightPos, TargetPos);

float lightLength = XMVector3Length(lightDir).m128_f32[0];

XMMATRIX lightView = XMMatrixLookAtLH(lightPos, TargetPos, lightUp);

// Transform bounding sphere to light space.

XMFLOAT3 xmf3CenterLS;

XMStoreFloat3(&xmf3CenterLS, XMVector3TransformCoord(XMLoadFloat3(&xmf3TargetPos), lightView));

// Ortho frustum in light space encloses scene.

float l = xmf3CenterLS.x - fBoundary;

float b = xmf3CenterLS.y - fBoundary;

float n = xmf3CenterLS.z - fBoundary;

float r = xmf3CenterLS.x + fBoundary;

float t = xmf3CenterLS.y + fBoundary;

float f = xmf3CenterLS.z + fBoundary;

XMMATRIX lightProj;

lightProj = XMMatrixOrthographicOffCenterLH(l, r, b, t, n, f);

// Transform NDC space [-1,+1]^2 to texture space [0,1]^2

XMMATRIX T(

0.5f, 0.0f, 0.0f, 0.0f,

0.0f, -0.5f, 0.0f, 0.0f,

0.0f, 0.0f, 1.0f, 0.0f,

0.5f, 0.5f, 0.0f, 1.0f);

XMMATRIX S = lightView * lightProj;

XMStoreFloat4x4(&m_xmf4x4LightViewProj[nShadowIndex], XMMatrixTranspose(S));

S = S * T;

XMStoreFloat4x4(&m_xmf4x4ShadowTransform[nShadowIndex], XMMatrixTranspose(S));

CB_SHADOW cbShadow{ m_xmf4x4ShadowTransform, m_xmf4x4LightViewProj, m_pLight->GetPosition(), m_xmf4x4CascadedViewProj};

m_ubShadowCB->CopyData(0, cbShadow);

pd3dCommandList->SetGraphicsRootConstantBufferView(3, m_ubShadowCB->Resource()->GetGPUVirtualAddress());

pd3dCommandList->SetGraphicsRoot32BitConstants(2, 1, &nShadowIndex, 1);

}