Hello,
I know, it's me again but I run into another strange problem and I am stuck in one place :\
I want to project a shadow map but renderTarget seems unable to be clamped (i set it from both xna and hlsl to pointClamp).
Even after manually clamping it in the shader It got extruded towards light position.
Picture will better explain the situation so I attach one (green line is where the projected texture should be cut off, and the ball in front of the car is lookAt point, and bellow normal buffer you see light view).
Here's HLSL code:
[source lang="cpp"]float3 DepthToPosition(float2 TexCoord)
{
float4 position;
float d = tex2D(depth, TexCoord.xy);
position.x = TexCoord.x * 2.0f - 1.0f;
position.y = -(TexCoord.y * 2.0f - 1.0f);
position.z = d;
position.w = 1.0f;
position = mul(position, InvertViewProjection);
position /= position.w;
return position;
}
float4 SpotShadow(VertexShaderOutput input) : COLOR0
{
float3 Position = DepthToPosition(input.TexCoord);
float4 texcoord = mul(float4(Position, 1.0), LightWorldViewProjection);
if(texcoord.z < 0)
return float4(1,0,0,1);
texcoord.x = ((texcoord.x / texcoord.w) * 0.5 ) + 0.5;
texcoord.y = ((texcoord.y / texcoord.w) * -0.5 ) + 0.5;
if(texcoord.x < 0 || texcoord.x > 1 || texcoord.y < 0 || texcoord.x > 1)
return float4(1,0,0,1);
float LightDistance = (tex2D(shadow, texcoord.xy));
return LightDistance;
}[/source]
I think I don't have to say i want to get rid of this if that is checking coords
But also I want to know why does it extrude projected texture towards light camera and how to reapir it
Thank You in advance

That definitely does look weird, something more sinister looks to be afoot. Have you tried taking it into PIX and seeing what is actually sampling at the extruded spots?

To be onest I have never used PIX. I will try that in a few hours.
What You see I use with spotlight which projects light shape (black and white mask), which works fine. But I want to make a CSM and I am very concerned about this:)
It's first time I get this with spotlight o.O

Your light looks to be over the hood of the car, but it's shading areas behind the light

I worte that the ball in front of the car is lookAt point The light is at the top of that triangular shape (if you want I can reupload image with dot in light position).

As far as PIX goes, MJP has a really good tutorial for it: (http://mynameismjp.w...h-xna-tutorial/)

Thanks! I was thinking about asking for tutorial, but you were faster And I like MJP tutorials, they are very clear

I feel ashamed to admit it but it was a typo...
In the last comparison in if statment there's x instead of y (at least i learnt basic stuff wiht PIX ).
Ok to make up for that here's what happenes with clamps made like that:
[source lang="cpp"]
//hlsl sampler declaration

texture ShadowMap;
sampler shadow = sampler_state
{
Texture = (ShadowMap);
AddressU = CLAMP;
AddressV = CLAMP;
MagFilter = POINT;
MinFilter = POINT;
Mipfilter = POINT;
};

//XNA side before draw call:

device.SamplerStates[0] = SamplerState.PointClamp;
device.SamplerStates[1] = SamplerState.PointClamp;
device.SamplerStates[2] = SamplerState.PointClamp;
device.SamplerStates[3] = SamplerState.PointClamp;[/source]
Left one is with if inside shader, right one is without. Why clamp doesn't work like that?

To the PIX!

PIX said it's clamped. Maybe I understand clamp the wrong way...
I will describe it how I understand clamping:
When texture's sampler state is set to uv clamp, tex2D returns transparent value when either u or v is out of [0,1] range.
When it's set to wrap, when u or v is, for instance, 1.1 tex2D reads it as 0.1 and thus we can make tiling.