• 10
• 9
• 13
• 10
• 18
• ### Similar Content

• By cozzie
Hi all,
As a part of the debug drawing system in my engine,  I want to add support for rendering simple text on screen  (aka HUD/ HUD style). From what I've read there are a few options, in short:
1. Write your own font sprite renderer
2. Using Direct2D/Directwrite, combine with DX11 rendertarget/ backbuffer
3. Use an external library, like the directx toolkit etc.
I want to go for number 2, but articles/ documentation confused me a bit. Some say you need to create a DX10 device, to be able to do this, because it doesn't directly work with the DX11 device.  But other articles tell that this was 'patched' later on and should work now.
Can someone shed some light on this and ideally provide me an example or article on  how to set this up?
All input is appreciated.
• By stale
I've just started learning about tessellation from Frank Luna's DX11 book. I'm getting some very weird behavior when I try to render a tessellated quad patch if I also render a mesh in the same frame. The tessellated quad patch renders just fine if it's the only thing I'm rendering. This is pictured below:
'
However, when I attempt to render the same tessellated quad patch along with the other entities in the scene (which are simple triangle-lists), I get the following error:

I have no idea why this is happening, and google searches have given me no leads at all. I use the following code to render the tessellated quad patch:
for (unsigned int i = 0; i < scene->GetEntityList()->size(); i++) { Entity* entity = scene->GetEntityList()->at(i); if (entity->m_VisualComponent->m_visualType == VisualType::MESH) DrawMeshEntity(entity, cam, sun, point); else if (entity->m_VisualComponent->m_visualType == VisualType::BILLBOARD) DrawBillboardEntity(entity, cam, sun, point); else if (entity->m_VisualComponent->m_visualType == VisualType::TERRAIN) DrawTerrainEntity(entity, cam); } HR(m_swapChain->Present(0, 0)); Any help/advice would be much appreciated!

• Am trying a basebones tessellation shader and getting unexpected result when increasing the tessellation factor. Am rendering a group of quads and trying to apply tessellation to them.
OutsideTess = (1,1,1,1), InsideTess= (1,1)

OutsideTess = (1,1,1,1), InsideTess= (2,1)

I expected 4 triangles in the quad, not two. Any idea of whats wrong?
Structs:
struct PatchTess { float mEdgeTess[4] : SV_TessFactor; float mInsideTess[2] : SV_InsideTessFactor; }; struct VertexOut { float4 mWorldPosition : POSITION; float mTessFactor : TESS; }; struct DomainOut { float4 mWorldPosition : SV_POSITION; }; struct HullOut { float4 mWorldPosition : POSITION; }; Hull shader:
PatchTess PatchHS(InputPatch<VertexOut, 3> inputVertices) { PatchTess patch; patch.mEdgeTess[ 0 ] = 1; patch.mEdgeTess[ 1 ] = 1; patch.mEdgeTess[ 2 ] = 1; patch.mEdgeTess[ 3 ] = 1; patch.mInsideTess[ 0 ] = 2; patch.mInsideTess[ 1 ] = 1; return patch; } [domain("quad")] [partitioning("fractional_odd")] [outputtopology("triangle_ccw")] [outputcontrolpoints(4)] [patchconstantfunc("PatchHS")] [maxtessfactor( 64.0 )] HullOut hull_main(InputPatch<VertexOut, 3> verticeData, uint index : SV_OutputControlPointID) { HullOut ret; ret.mWorldPosition = verticeData[index].mWorldPosition; return ret; }
[domain("quad")] DomainOut domain_main(PatchTess patchTess, float2 uv : SV_DomainLocation, const OutputPatch<HullOut, 4> quad) { DomainOut ret; const float MipInterval = 20.0f; ret.mWorldPosition.xz = quad[ 0 ].mWorldPosition.xz * ( 1.0f - uv.x ) * ( 1.0f - uv.y ) + quad[ 1 ].mWorldPosition.xz * uv.x * ( 1.0f - uv.y ) + quad[ 2 ].mWorldPosition.xz * ( 1.0f - uv.x ) * uv.y + quad[ 3 ].mWorldPosition.xz * uv.x * uv.y ; ret.mWorldPosition.y = quad[ 0 ].mWorldPosition.y; ret.mWorldPosition.w = 1; ret.mWorldPosition = mul( gFrameViewProj, ret.mWorldPosition ); return ret; }
Any ideas what could be wrong with these shaders?
• By simco50
Hello,
I've stumbled upon Urho3D engine and found that it has a really nice and easy to read code structure.
I think the graphics abstraction looks really interesting and I like the idea of how it defers pipeline state changes until just before the draw call to resolve redundant state changes.
This is done by saving the state changes (blendEnabled/SRV changes/RTV changes) in member variables and just before the draw, apply the actual state changes using the graphics context.
It looks something like this (pseudo):
void PrepareDraw() { if(renderTargetsDirty) { pD3D11DeviceContext->OMSetRenderTarget(mCurrentRenderTargets); renderTargetsDirty = false } if(texturesDirty) { pD3D11DeviceContext->PSSetShaderResourceView(..., mCurrentSRVs); texturesDirty = false } .... //Some more state changes } This all looked like a great design at first but I've found that there is one big issue with this which I don't really understand how it is solved in their case and how I would tackle it.
I'll explain it by example, imagine I have two rendertargets: my backbuffer RT and an offscreen RT.
Say I want to render my backbuffer to the offscreen RT and then back to the backbuffer (Just for the sake of the example).
You would do something like this:
//Render to the offscreen RT pGraphics->SetRenderTarget(pOffscreenRT->GetRTV()); pGraphics->SetTexture(diffuseSlot, pDefaultRT->GetSRV()) pGraphics->DrawQuad() pGraphics->SetTexture(diffuseSlot, nullptr); //Remove the default RT from input //Render to the default (screen) RT pGraphics->SetRenderTarget(nullptr); //Default RT pGraphics->SetTexture(diffuseSlot, pOffscreenRT->GetSRV()) pGraphics->DrawQuad(); The problem here is that the second time the application loop comes around, the offscreen rendertarget is still bound as input ShaderResourceView when it gets set as a RenderTargetView because in Urho3D, the state of the RenderTargetView will always be changed before the ShaderResourceViews (see top code snippet) even when I set the SRV to nullptr before using it as a RTV like above causing errors because a resource can't be bound to both input and rendertarget.
What is usually the solution to this?

Thanks!
• By MehdiUBP
Hello,
I wrote a MatCap shader following this idea:
Given the image representing the texture, we compute the sample point by taking the dot product of the vertex normal and the camera position and remapping this to [0,1].
This seems to work well when I look straight at an object with this shader. However, in cases where the camera points slightly on the side, I can see the texture stretch a lot.
Could anyone give me a hint as how to get a nice matcap shader ?
Here's what I wrote:

{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work

#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float3 normal : NORMAL;
};
struct v2f
{
float2 worldNormal : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.worldNormal = mul((float3x3)UNITY_MATRIX_V, UnityObjectToWorldNormal(v.normal)).xy*0.3 + 0.5;  //UnityObjectToClipPos(v.normal)*0.5 + 0.5;
return o;
}

fixed4 frag (v2f i) : SV_Target
{
// sample the texture
fixed4 col = tex2D(_MainTex, i.worldNormal);
// apply fog
return col;
}
ENDCG
}
}
}

Thanks!

# DX11 SSAO Using 32-bit pixel format as NormalDepth Texturemap

This topic is 1612 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Hey Guys,
I'm doing Exercise5 Ch22 SSAO on Frank Luna's DX11 book, I used DXGI_FORMAT_R8G8B8A8_UNORM to replace DXGI_FORMAT_R16G16B16A16_FLOAT when building normalDepth texture map.
When using DXGI_FORMAT_R16G16B16A16_FLOAT, I store view space normal to RGB channel, the alpha channel stores the view space depth(z-coordinate). Now using DXGI_FORMAT_R8G8B8A8_UNORM, I store normal vector x- and y- coordinate to RG channel, and BA combined store 16-bit depth value.
I construct the normal z-coordinate by nz = -sqrt(1-x^2-y^2).
To store the view space depth over two 8-bit UNORM channels, I normalized z to [0, 1] by dividing by the far plane depth zFar. Then I used a little tricks to save 8 most and 8 least significant digits to BA 16-bit channels(following code below).
When rendering normal and depth values of the scene to the DXGI_FORMAT_R8G8B8A8_UNORM 2D texture, the main code is

cbuffer cbPerScene
{
float gZFar;
};

struct VertexIn
{
float3 PosL    : POSITION;
float3 NormalL : NORMAL;
float2 Tex     : TEXCOORD;
};

struct VertexOut
{
float4 PosH       : SV_POSITION;
float3 PosV       : POSITION;
float3 NormalV    : NORMAL;
float2 Tex        : TEXCOORD0;
};

VertexOut VS(VertexIn vin)
{
VertexOut vout;

// Transform to view space.
vout.PosV    = mul(float4(vin.PosL, 1.0f), gWorldView).xyz;
vout.NormalV = mul(vin.NormalL, (float3x3)gWorldInvTransposeView);

// Transform to homogeneous clip space.
vout.PosH = mul(float4(vin.PosL, 1.0f), gWorldViewProj);

// Output vertex attributes for interpolation across triangle.
vout.Tex = mul(float4(vin.Tex, 0.0f, 1.0f), gTexTransform).xy;

return vout;
}

float4 PS(VertexOut pin, uniform bool gAlphaClip) : SV_Target
{
// Interpolating normal can unnormalize it, so normalize it.
pin.NormalV = normalize(pin.NormalV);

if(gAlphaClip)
{
float4 texColor = gDiffuseMap.Sample( samLinear, pin.Tex );

clip(texColor.a - 0.1f);
}

float4 normalDepth = float4(0, 0, 0, 0);
normalDepth.rg = pin.NormalV.rg;
float depth = pin.PosV.b;
float z = depth / gZFar;
normalDepth.ba = float2(z, frac(256.0f*z));
return normalDepth;
}

technique11 NormalDepth
{
pass P0
{
}
}


When using this DXGI_FORMAT_R8G8B8A8_UNORM texture to build SSAO, the main code is

cbuffer cbPerFrame
{
float4x4 gViewToTexSpace; // Proj*Texture
float4   gOffsetVectors[14];
float4   gFrustumCorners[4];
float     gZFar;

// Coordinates given in view space.
float    gSurfaceEpsilon     = 0.05f;
};

Texture2D gNormalDepthMap;
Texture2D gRandomVecMap;

SamplerState samNormalDepth
{
Filter = MIN_MAG_LINEAR_MIP_POINT;

// Set a very far depth value if sampling outside of the NormalDepth map
// so we do not get false occlusions.
BorderColor = float4(0.0f, 0.0f, 0.0f, 1e5f);
};

SamplerState samRandomVec
{
Filter = MIN_MAG_LINEAR_MIP_POINT;
};

struct VertexIn
{
float3 PosL            : POSITION;
float3 ToFarPlaneIndex : NORMAL;
float2 Tex             : TEXCOORD;
};

struct VertexOut
{
float4 PosH       : SV_POSITION;
float3 ToFarPlane : TEXCOORD0;
float2 Tex        : TEXCOORD1;
};

VertexOut VS(VertexIn vin)
{
VertexOut vout;

vout.PosH = float4(vin.PosL, 1.0f);

// We store the index to the frustum corner in the normal x-coord slot.
vout.ToFarPlane = gFrustumCorners[vin.ToFarPlaneIndex.x].xyz;

vout.Tex = vin.Tex;

return vout;
}

// Determines how much the sample point q occludes the point p as a function
// of distZ.
float OcclusionFunction(float distZ)
{
//
// If depth(q) is "behind" depth(p), then q cannot occlude p.  Moreover, if
// depth(q) and depth(p) are sufficiently close, then we also assume q cannot
// occlude p because q needs to be in front of p by Epsilon to occlude p.
//
// We use the following function to determine the occlusion.
//
//
//       1.0     -------------\
//               |           |  \
//               |           |    \
//               |           |      \
//               |           |        \
//               |           |          \
//               |           |            \
//  ------|------|-----------|-------------|---------|--> zv
//        0     Eps          z0            z1
//

float occlusion = 0.0f;
if(distZ > gSurfaceEpsilon)
{

// Linearly decrease occlusion from 1 to 0 as distZ goes
}

return occlusion;
}

float4 PS(VertexOut pin, uniform int gSampleCount) : SV_Target
{
// p -- the point we are computing the ambient occlusion for.
// n -- normal vector at p.
// q -- a random offset from p.
// r -- a potential occluder that might occlude p.

// Get viewspace normal and z-coord of this pixel.  The tex-coords for
float4 normalDepth = gNormalDepthMap.SampleLevel(samNormalDepth, pin.Tex, 0.0f);

float2 nxy = normalDepth.rg;
float nz = sqrt(1 - pow(nxy.r, 2) - pow(nxy.g, 2));
nz = -nz;
float3 n = float3(nxy, nz);
float pz = normalDepth.b + normalDepth.a/256.0f;
pz *= gZFar;

//
// Reconstruct full view space position (x,y,z).
// Find t such that p = t*pin.ToFarPlane.
// p.z = t*pin.ToFarPlane.z
// t = p.z / pin.ToFarPlane.z
//
float3 p = (pz/pin.ToFarPlane.z)*pin.ToFarPlane;

// Extract random vector and map from [0,1] --> [-1, +1].
float3 randVec = 2.0f*gRandomVecMap.SampleLevel(samRandomVec, 4.0f*pin.Tex, 0.0f).rgb - 1.0f;

float occlusionSum = 0.0f;

// Sample neighboring points about p in the hemisphere oriented by n.
[unroll]
for(int i = 0; i < gSampleCount; ++i)
{
// Are offset vectors are fixed and uniformly distributed (so that our offset vectors
// do not clump in the same direction).  If we reflect them about a random vector
// then we get a random uniform distribution of offset vectors.
float3 offset = reflect(gOffsetVectors[i].xyz, randVec);

// Flip offset vector if it is behind the plane defined by (p, n).
float flip = sign( dot(offset, n) );

// Sample a point near p within the occlusion radius.
float3 q = p + flip * gOcclusionRadius * offset;

// Project q and generate projective tex-coords.
float4 projQ = mul(float4(q, 1.0f), gViewToTexSpace);
projQ /= projQ.w;

// Find the nearest depth value along the ray from the eye to q (this is not
// the depth of q, as q is just an arbitrary point near p and might
// occupy empty space).  To find the nearest depth we look it up in the depthmap.

float2 rz = gNormalDepthMap.SampleLevel(samNormalDepth, projQ.xy, 0.0f).ba;
float rpz = rz.r + rz.g/256.0f;
rpz *= gZFar;

// Reconstruct full view space position r = (rx,ry,rz).  We know r
// lies on the ray of q, so there exists a t such that r = t*q.
// r.z = t*q.z ==> t = r.z / q.z

float3 r = (rpz / q.z) * q;

//
// Test whether r occludes p.
//   * The product dot(n, normalize(r - p)) measures how much in front
//     of the plane(p,n) the occluder point r is.  The more in front it is, the
//     more occlusion weight we give it.  This also prevents self shadowing where
//     a point r on an angled plane (p,n) could give a false occlusion since they
//     have different depth values with respect to the eye.
//   * The weight of the occlusion is scaled based on how far the occluder is from
//     the point we are computing the occlusion of.  If the occluder r is far away
//     from p, then it does not occlude it.
//

float distZ = p.z - r.z;
float dp = max(dot(n, normalize(r - p)), 0.0f);
float occlusion = dp * OcclusionFunction(distZ);

occlusionSum += occlusion;
}

occlusionSum /= gSampleCount;

float access = 1.0f - occlusionSum;

// Sharpen the contrast of the SSAO map to make the SSAO affect more dramatic.
return saturate(pow(access, 4.0f));
}

technique11 Ssao
{
pass P0
{
}
}


When I check the SSAO texture before bluring with camera to an angle, the image is

[attachment=18446:2013-10-19_164907.jpg]

and then I move camera to the right, the image is

[attachment=18447:2013-10-19_170115.jpg]

Basically, when I move camera, the black and white areas vary heavily in the SSAO image.It's like getting an annoying amount of halo-ing on these surfaces.

The image below is the original SSAO image before bluring using DXGI_FORMAT_R16G16B16A16_FLOAT

[attachment=18448:2013-10-19_170332.jpg]

The false display has something to do with view position and orientation, I tried to modify the cosntants value in OcclusionFunction, such as gOcclusionRadius, but it didn't work, not apparently..

How can I wipe out the wrong dark display when it's not occluded? What could be causing this?

Thank you very much.

##### Share on other sites

Since the only thing you changed was the format of the texture, and the corresponding mechanisms for reading/writing the texture, then I would assume that there is an issue in the code somewhere, or there is an inherent problem with using a low resolution texture for the data you need.

Have you tried to visualize the depth/normal texture prior to it being used?  This will likely give you a great insight into whether or not you are accurately reproducing the same data.  Create a simple shader to read the normal information and display in both the old code and the new code - then you can quickly see the differences visually.  If that looks reasonably similar, then I would check on the depth channels as well - make a similar before and after comparison.

It is just a hunch, but since you said you use a 'clever' trick for storing the upper and lower 8 bits into separate channels, I would suspect this as a potential issue.  Have you validated your technique with some test values?  Done any shader debugging to watch what value comes out of the reading functions?  Start here, and you should be able to find the issue.

##### Share on other sites

Could it be that your x,y position values are just too in accurate. Consider that there is only 256 different values for x,y positions and your buffer resolution is already bigger than each of the values?

Why not just store the depth and reconstruct the position from screen space x,y positions and the depth.

Cheers!

##### Share on other sites

Hey Guys, I'm back

Like Jason Z suggested, I tried to visualize the Normal Depth texture before and after using on next stage. I compare these two on R G B A channel respectively, which indicates normal_x normal_y depthz_hi8bits depthz_lo8bits. the result showing below.

[attachment=18458:2013-10-20_red.jpg]

upper-right is after,  lower-right is before [R]

[attachment=18459:2013-10-20_green.jpg]

upper-right is after,  lower-right is before [G]

[attachment=18460:2013-10-20_blue.jpg]

upper-right is after,  lower-right is before

[attachment=18461:2013-10-20_alpha.jpg]

upper-right is after,  lower-right is before [A]

Observing these results, I found they're all corresponding to each other, However, I found halo-ing thing happening on A channel display just like zebra line, which is added to the final image. It's because A channel stores 8 low bits of depth z value, which varies heavily even on the same surface inherently, hence, I think the final image with halo-ing kind of thing has something related to it. I shall continue research on it

##### Share on other sites

Could it be that your x,y position values are just too in accurate. Consider that there is only 256 different values for x,y positions and your buffer resolution is already bigger than each of the values?

Why not just store the depth and reconstruct the position from screen space x,y positions and the depth.

Cheers!

Hi kauna

through tests with images above, I think a 2-8bit format storing x,y of normal values is OK. Maybe this weird display is due to some process with the low 8 bits of depth value.

Thanks anyway!