• Advertisement
Sign in to follow this  

DX11 nvidia rain demo

This topic is 2113 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

I'm trying to render rain with dx11 and hlsl and there aren't a lot of examples to create realistic rain. The best I've found so far is nvidia's rain demo from their directx 10 sdk. I've managed to convert it to directx 11 and it is working but I'm having hard time to understand the main part of their code which i added below.
My first problem is how they indexed their streak images. There are 370 rain streak images and if I'm not mistaken the maximum index value can be 368.
And my second problem is "if"s in the code. I didn't understand their purpose. And why they are using is_EpLp_angle_ccw to invert only one of the horizontal texture coordinates.
Also if there are any other rain tutorial that you can suggest I would like to check it out.

[code]void rainResponse(PSSceneIn input, float3 lightVector, float lightIntensity, float3 lightColor, float3 eyeVector, bool fallOffFactor, inout float4 rainResponseVal)
{

float opacity = 0.0;
float fallOff;
if(fallOffFactor)
{
float distToLight = length(lightVector);
fallOff = 1.0/( distToLight * distToLight);
fallOff = saturate(fallOff);
}
else
{ fallOff = 1;
}
if(fallOff > 0.01 && lightIntensity > 0.01 )
{
float3 dropDir = g_TotalVel;
#define MAX_VIDX 4
#define MAX_HIDX 8
// Inputs: lightVector, eyeVector, dropDir
float3 L = normalize(lightVector);
float3 E = normalize(eyeVector);
float3 N = normalize(dropDir);

bool is_EpLp_angle_ccw = true;
float hangle = 0;
float vangle = abs( (acos(dot(L,N)) * 180/PI) - 90 ); // 0 to 90

{
float3 Lp = normalize( L - dot(L,N)*N );
float3 Ep = normalize( E - dot(E,N)*N );
hangle = acos( dot(Ep,Lp) ) * 180/PI; // 0 to 180
hangle = (hangle-10)/20.0; // -0.5 to 8.5
is_EpLp_angle_ccw = dot( N, cross(Ep,Lp)) > 0;
}

if(vangle>=88.0)
{
hangle = 0;
is_EpLp_angle_ccw = true;
}

vangle = (vangle-10.0)/20.0; // -0.5 to 4.5

// Outputs:
// verticalLightIndex[1|2] - two indices in the vertical direction
// t - fraction at which the vangle is between these two indices (for lerp)
int verticalLightIndex1 = floor(vangle); // 0 to 5
int verticalLightIndex2 = min(MAX_VIDX, (verticalLightIndex1 + 1) );
verticalLightIndex1 = max(0, verticalLightIndex1);
float t = frac(vangle);
// textureCoordsH[1|2] used in case we need to flip the texture horizontally
float textureCoordsH1 = input.tex.x;
float textureCoordsH2 = input.tex.x;

// horizontalLightIndex[1|2] - two indices in the horizontal direction
// s - fraction at which the hangle is between these two indices (for lerp)
int horizontalLightIndex1 = 0;
int horizontalLightIndex2 = 0;
float s = 0;

s = frac(hangle);
horizontalLightIndex1 = floor(hangle); // 0 to 8
horizontalLightIndex2 = horizontalLightIndex1+1;
if( horizontalLightIndex1 < 0 )
{
horizontalLightIndex1 = 0;
horizontalLightIndex2 = 0;
}

if( is_EpLp_angle_ccw )
{
if( horizontalLightIndex2 > MAX_HIDX )
{
horizontalLightIndex2 = MAX_HIDX;
textureCoordsH2 = 1.0 - textureCoordsH2;
}
}
else
{
textureCoordsH1 = 1.0 - textureCoordsH1;
if( horizontalLightIndex2 > MAX_HIDX )
{
horizontalLightIndex2 = MAX_HIDX;
} else
{
textureCoordsH2 = 1.0 - textureCoordsH2;
}
}

if( verticalLightIndex1 >= MAX_VIDX )
{
textureCoordsH2 = input.tex.x;
horizontalLightIndex1 = 0;
horizontalLightIndex2 = 0;
s = 0;
}

// Generate the final texture coordinates for each sample
uint type = input.type;
uint2 texIndicesV1 = uint2(verticalLightIndex1*90 + horizontalLightIndex1*10 + type,
verticalLightIndex1*90 + horizontalLightIndex2*10 + type);
float3 tex1 = float3(textureCoordsH1, input.tex.y, texIndicesV1.x);
float3 tex2 = float3(textureCoordsH2, input.tex.y, texIndicesV1.y);
if( (verticalLightIndex1<4) && (verticalLightIndex2>=4) )
{
s = 0;
horizontalLightIndex1 = 0;
horizontalLightIndex2 = 0;
textureCoordsH1 = input.tex.x;
textureCoordsH2 = input.tex.x;
}

uint2 texIndicesV2 = uint2(verticalLightIndex2*90 + horizontalLightIndex1*10 + type,
verticalLightIndex2*90 + horizontalLightIndex2*10 + type);
float3 tex3 = float3(textureCoordsH1, input.tex.y, texIndicesV2.x);
float3 tex4 = float3(textureCoordsH2, input.tex.y, texIndicesV2.y);
// Sample opacity from the textures
float col1 = rainTextureArray.Sample( samAniso, tex1) * g_rainfactors[texIndicesV1.x];
float col2 = rainTextureArray.Sample( samAniso, tex2) * g_rainfactors[texIndicesV1.y];
float col3 = rainTextureArray.Sample( samAniso, tex3) * g_rainfactors[texIndicesV2.x];
float col4 = rainTextureArray.Sample( samAniso, tex4) * g_rainfactors[texIndicesV2.y];
// Compute interpolated opacity using the s and t factors
float hOpacity1 = lerp(col1,col2,s);
float hOpacity2 = lerp(col3,col4,s);
opacity = lerp(hOpacity1,hOpacity2,t);
opacity = pow(opacity,0.7); // inverse gamma correction (expand dynamic range)
opacity = 4*lightIntensity * opacity * fallOff;
}

rainResponseVal = float4(lightColor,opacity);
}[/code]

Share this post


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

  • Advertisement
  • Advertisement
  • Popular Now

  • Advertisement
  • Similar Content

    • By AxeGuywithanAxe
      I wanted to see how others are currently handling descriptor heap updates and management.
      I've read a few articles and there tends to be three major strategies :
      1 ) You split up descriptor heaps per shader stage ( i.e one for vertex shader , pixel , hull, etc)
      2) You have one descriptor heap for an entire pipeline
      3) You split up descriptor heaps for update each update frequency (i.e EResourceSet_PerInstance , EResourceSet_PerPass , EResourceSet_PerMaterial, etc)
      The benefits of the first two approaches is that it makes it easier to port current code, and descriptor / resource descriptor management and updating tends to be easier to manage, but it seems to be not as efficient.
      The benefits of the third approach seems to be that it's the most efficient because you only manage and update objects when they change.
    • By evelyn4you
      hi,
      until now i use typical vertexshader approach for skinning with a Constantbuffer containing the transform matrix for the bones and an the vertexbuffer containing bone index and bone weight.
      Now i have implemented realtime environment  probe cubemaping so i have to render my scene from many point of views and the time for skinning takes too long because it is recalculated for every side of the cubemap.
      For Info i am working on Win7 an therefore use one Shadermodel 5.0 not 5.x that have more options, or is there a way to use 5.x in Win 7
      My Graphic Card is Directx 12 compatible NVidia GTX 960
      the member turanszkij has posted a good for me understandable compute shader. ( for Info: in his engine he uses an optimized version of it )
      https://turanszkij.wordpress.com/2017/09/09/skinning-in-compute-shader/
      Now my questions
       is it possible to feed the compute shader with my orignial vertexbuffer or do i have to copy it in several ByteAdressBuffers as implemented in the following code ?
        the same question is about the constant buffer of the matrixes
       my more urgent question is how do i feed my normal pipeline with the result of the compute Shader which are 2 RWByteAddressBuffers that contain position an normal
      for example i could use 2 vertexbuffer bindings
      1 containing only the uv coordinates
      2.containing position and normal
      How do i copy from the RWByteAddressBuffers to the vertexbuffer ?
       
      (Code from turanszkij )
      Here is my shader implementation for skinning a mesh in a compute shader:
      1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 struct Bone { float4x4 pose; }; StructuredBuffer<Bone> boneBuffer;   ByteAddressBuffer vertexBuffer_POS; // T-Pose pos ByteAddressBuffer vertexBuffer_NOR; // T-Pose normal ByteAddressBuffer vertexBuffer_WEI; // bone weights ByteAddressBuffer vertexBuffer_BON; // bone indices   RWByteAddressBuffer streamoutBuffer_POS; // skinned pos RWByteAddressBuffer streamoutBuffer_NOR; // skinned normal RWByteAddressBuffer streamoutBuffer_PRE; // previous frame skinned pos   inline void Skinning(inout float4 pos, inout float4 nor, in float4 inBon, in float4 inWei) {  float4 p = 0, pp = 0;  float3 n = 0;  float4x4 m;  float3x3 m3;  float weisum = 0;   // force loop to reduce register pressure  // though this way we can not interleave TEX - ALU operations  [loop]  for (uint i = 0; ((i &lt; 4) &amp;&amp; (weisum&lt;1.0f)); ++i)  {  m = boneBuffer[(uint)inBon].pose;  m3 = (float3x3)m;   p += mul(float4(pos.xyz, 1), m)*inWei;  n += mul(nor.xyz, m3)*inWei;   weisum += inWei;  }   bool w = any(inWei);  pos.xyz = w ? p.xyz : pos.xyz;  nor.xyz = w ? n : nor.xyz; }   [numthreads(1024, 1, 1)] void main( uint3 DTid : SV_DispatchThreadID ) {  const uint fetchAddress = DTid.x * 16; // stride is 16 bytes for each vertex buffer now...   uint4 pos_u = vertexBuffer_POS.Load4(fetchAddress);  uint4 nor_u = vertexBuffer_NOR.Load4(fetchAddress);  uint4 wei_u = vertexBuffer_WEI.Load4(fetchAddress);  uint4 bon_u = vertexBuffer_BON.Load4(fetchAddress);   float4 pos = asfloat(pos_u);  float4 nor = asfloat(nor_u);  float4 wei = asfloat(wei_u);  float4 bon = asfloat(bon_u);   Skinning(pos, nor, bon, wei);   pos_u = asuint(pos);  nor_u = asuint(nor);   // copy prev frame current pos to current frame prev pos streamoutBuffer_PRE.Store4(fetchAddress, streamoutBuffer_POS.Load4(fetchAddress)); // write out skinned props:  streamoutBuffer_POS.Store4(fetchAddress, pos_u);  streamoutBuffer_NOR.Store4(fetchAddress, nor_u); }  
    • By mister345
      Hi, can someone please explain why this is giving an assertion EyePosition!=0 exception?
       
      _lightBufferVS->viewMatrix = DirectX::XMMatrixLookAtLH(XMLoadFloat3(&_lightBufferVS->position), XMLoadFloat3(&_lookAt), XMLoadFloat3(&up));
      It looks like DirectX doesnt want the 2nd parameter to be a zero vector in the assertion, but I passed in a zero vector with this exact same code in another program and it ran just fine. (Here is the version of the code that worked - note XMLoadFloat3(&m_lookAt) parameter value is (0,0,0) at runtime - I debugged it - but it throws no exceptions.
          m_viewMatrix = DirectX::XMMatrixLookAtLH(XMLoadFloat3(&m_position), XMLoadFloat3(&m_lookAt), XMLoadFloat3(&up)); Here is the repo for the broken code (See LightClass) https://github.com/mister51213/DirectX11Engine/blob/master/DirectX11Engine/LightClass.cpp
      and here is the repo with the alternative version of the code that is working with a value of (0,0,0) for the second parameter.
      https://github.com/mister51213/DX11Port_SoftShadows/blob/master/Engine/lightclass.cpp
    • By mister345
      Hi, can somebody please tell me in clear simple steps how to debug and step through an hlsl shader file?
      I already did Debug > Start Graphics Debugging > then captured some frames from Visual Studio and
      double clicked on the frame to open it, but no idea where to go from there.
       
      I've been searching for hours and there's no information on this, not even on the Microsoft Website!
      They say "open the  Graphics Pixel History window" but there is no such window!
      Then they say, in the "Pipeline Stages choose Start Debugging"  but the Start Debugging option is nowhere to be found in the whole interface.
      Also, how do I even open the hlsl file that I want to set a break point in from inside the Graphics Debugger?
       
      All I want to do is set a break point in a specific hlsl file, step thru it, and see the data, but this is so unbelievably complicated
      and Microsoft's instructions are horrible! Somebody please, please help.
       
       
       

    • By mister345
      I finally ported Rastertek's tutorial # 42 on soft shadows and blur shading. This tutorial has a ton of really useful effects and there's no working version anywhere online.
      Unfortunately it just draws a black screen. Not sure what's causing it. I'm guessing the camera or ortho matrix transforms are wrong, light directions, or maybe texture resources not being properly initialized.  I didnt change any of the variables though, only upgraded all types and functions DirectX3DVector3 to XMFLOAT3, and used DirectXTK for texture loading. If anyone is willing to take a look at what might be causing the black screen, maybe something pops out to you, let me know, thanks.
      https://github.com/mister51213/DX11Port_SoftShadows
       
      Also, for reference, here's tutorial #40 which has normal shadows but no blur, which I also ported, and it works perfectly.
      https://github.com/mister51213/DX11Port_ShadowMapping
       
  • Advertisement