Ive been having a problem with a sort of white halo showing up around the blocks in my XNA game. When I debugged it in pix, I noticed that it seems to occur in the directional light shader and that it doesnt happen when I set pix to "Force REF". I've attached images of what it looks like in pix on both "Unchanged" and "Force REF" mode. What would cause this kind of thing?
Unchanged:
[attachment=8351:normal.png]
Force REF:
[attachment=8352:ref.png]
Artifacts in image that dont appear when using reference device
And what is the surface format of the depth buffer and how do you store the depth information?
You could suffer a lack of precision in the depth buffer.
You could suffer a lack of precision in the depth buffer.
Author
These are the render targets used by the deferred renderer:
In the GBuffer vertex shader I have
colorRT = new RenderTarget2D(Engine.Game.GraphicsDevice, backbufferWidth, backbufferHeight, false, SurfaceFormat.Color, DepthFormat.Depth24);
normalRT = new RenderTarget2D(Engine.Game.GraphicsDevice, backbufferWidth, backbufferHeight, false, SurfaceFormat.Color, DepthFormat.None);
depthRT = new RenderTarget2D(Engine.Game.GraphicsDevice, backbufferWidth, backbufferHeight, false, SurfaceFormat.Single, DepthFormat.None);
lightRT = new RenderTarget2D(Engine.Game.GraphicsDevice, backbufferWidth, backbufferHeight, false, SurfaceFormat.Color, DepthFormat.None);
finalRT = new RenderTarget2D(Engine.Game.GraphicsDevice, backbufferWidth, backbufferHeight, false, SurfaceFormat.Color, DepthFormat.None);
In the GBuffer vertex shader I have
output.Depth = output.Position.zw; and in the pixel shader I have output.Depth = input.Depth.x / input.Depth.y
It's really strange. 
First I think in MSAA because deferred renderers and MSAA don’t work well together, since different fragments will use the same illumination information.
Then I think that the GPU depth buffer could has little differences with your depth buffer. But it looks ok.
I don't know.
First I think in MSAA because deferred renderers and MSAA don’t work well together, since different fragments will use the same illumination information.
Then I think that the GPU depth buffer could has little differences with your depth buffer. But it looks ok.
I don't know.
Author
I was looking through pix again and I noticed a line that said SetRenderState(D3DRS_MULTISAMPLEANTIALIAS, TRUE). So it looks like MSAA is on. I have no idea whats turning it on though. When the graphics device is created, I explicitly turned it off. I checked all the render targets, none of them turn it on either. Ideas?
Yes. Set multisampling in the method Graphics_PreparingDeviceSettings
When you don't explicitly set multisampling the render target constructor uses the system value. And the correct place to setting the multisampling count is this method.
private static void Graphics_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
{
Device.PresentationParameters.MultiSampleCount = 0;
}
When you don't explicitly set multisampling the render target constructor uses the system value. And the correct place to setting the multisampling count is this method.
Author
Hmm, that didn't work. I should note that the SetRenderState line I noticed occurs RIGHT before the directional light shader starts rendering. It seems like a shader/render target specific setting, but I can't find anything in the code that might be enabling it.
Game constructor:
And heres a snippit of the directional light render code path:
Game constructor:
public Craft()
{
Game = this;
Graphics = new GraphicsDeviceManager(this)
{
PreferredBackBufferWidth = 1280,
PreferredBackBufferHeight = 720,
SynchronizeWithVerticalRetrace = false,
PreferMultiSampling = false,
IsFullScreen = false
};
Graphics.PreparingDeviceSettings += graphics_PreparingDeviceSettings;
Content.RootDirectory = "Content";
IsFixedTimeStep = false;
//this.Window.AllowUserResizing = true;
//this.IsMouseVisible = true;
}
void graphics_PreparingDeviceSettings(object sender, PreparingDeviceSettingsEventArgs e)
{
foreach(GraphicsAdapter adapter in GraphicsAdapter.Adapters)
{
if(adapter.Description.Contains("PerfHUD"))
{
e.GraphicsDeviceInformation.Adapter = adapter;
GraphicsAdapter.UseReferenceDevice = true; // this is the modified line from usage in previous xna version
break;
}
}
e.GraphicsDeviceInformation.PresentationParameters.MultiSampleCount = 0;
}
And heres a snippit of the directional light render code path:
class DeferredRenderer
{
private void DrawLights()
{
Engine.Graphics.GraphicsDevice.SetRenderTarget(lightRT);
Engine.Graphics.GraphicsDevice.Clear(Color.Transparent);
Engine.Graphics.GraphicsDevice.BlendState = BlendState.AlphaBlend;
Engine.Graphics.GraphicsDevice.DepthStencilState = DepthStencilState.None;
DirectionalLight.Draw();
PointLight.Draw();
Engine.Graphics.GraphicsDevice.BlendState = BlendState.Opaque;
Engine.Graphics.GraphicsDevice.DepthStencilState = DepthStencilState.Default;
Engine.Graphics.GraphicsDevice.RasterizerState = RasterizerState.CullCounterClockwise;
Engine.Graphics.GraphicsDevice.SetRenderTarget(null);
}
}
class DirectionalLight
{
private void DrawDirectionalLight()
{
directionalLightEffect.Parameters["ColorMap"].SetValue(DeferredRenderer.ColorRT);
directionalLightEffect.Parameters["NormalMap"].SetValue(DeferredRenderer.NormalRT);
directionalLightEffect.Parameters["DepthMap"].SetValue(DeferredRenderer.DepthRT);
directionalLightEffect.Parameters["LightDirection"].SetValue(LightDirection);
directionalLightEffect.Parameters["DiffuseLightColor"].SetValue(DiffuseColor);
directionalLightEffect.Parameters["AmbientLightColor"].SetValue(AmbientColor);
directionalLightEffect.Parameters["AmbientIntensity"].SetValue(AmbientIntensity);
directionalLightEffect.Parameters["DiffuseIntensity"].SetValue(DiffuseIntensity);
directionalLightEffect.Parameters["SpecularPower"].SetValue(SpecularPower);
directionalLightEffect.Parameters["SpecularIntensity"].SetValue(SpecularIntensity);
directionalLightEffect.Parameters["CameraPosition"].SetValue(Camera.Position);
directionalLightEffect.Parameters["InvertViewProjection"].SetValue(Matrix.Invert(Camera.View * Camera.Projection));
directionalLightEffect.Techniques[0].Passes[0].Apply();
DeferredRenderer.FullScreenQuad.Draw();
}
public static void Draw()
{
foreach(DirectionalLight light in lights)
{
light.DrawDirectionalLight();
}
}
}
Everything looks good.
Maybe it’s a driver problem. Upload your bin directory, I will try your program if you like.
Maybe it’s a driver problem. Upload your bin directory, I will try your program if you like.
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