I'm new to shadow mapping. I've followed some tutes on the net, but can't get this working.

I've created a terrain using a heightmap and textured it comparing slope and height. All that's working.

Then I tried getting shadows to work. I've created a shadow map by using the orthographic projection (for the sun) - projection matrix and view matrix from the light. I've translated the current vertex/pixel to light-space. I then used a texture sampler to lookup depth value from the shadow map texture. At the moment I'm just testing if a pixel is in shadow or not. If it's in shadow I add the shadow by darkening the pixel. I've checked the tutes and my code "seems" OK, but no shadows show up. I've attached the shadow map the was generated and some HLSL code.

Vertex Shader:

...

output.LightPosition = mul(input.Position, lightWorldViewProj);

output.LightPosition /= output.LightPosition.w;

return output;

}

Pixel Shader:

...

float2projectedTexCoords;

projectedTexCoords[0] = input.LightPosition.x / 2.0f + 0.5f;

projectedTexCoords[1] = input.LightPosition.y / -2.0f + 0.5f;

float depthStoredInShadowMap = shadowMap.Sample(shadowMapSampler, projectedTexCoords).r;

float realDistance = input.LightPosition.z;

if ((realDistance - 1.0f / 100.0f) <= depthStoredInShadowMap)

{

colour.xyz *= 0.25f;

}

return colour;

}

edit: It seems that the line float depthStoredInShadowMap = shadowMap.Sample(shadowMapSampler, projectedTexCoords).r; is always returning zero??

What is happening??

Right, so no-one has an idea what's going on then? Guess I'm never going to finish this - damn.

As I'm using SharpDX I posted their forums and found out that I need to set the render target before binding the shadow map.

Now it renders shadows - there not quite right yet, but at least I have something to work with.

I've set the size of shadow map to equal the window client size so 800x600., but the window size can be changed - that doesn't cause any problems.

I am still having trouble with shadows though. At lease the shadow map is actually adding shadows now, but shadows still aren't right.

Maybe something to do with converting the current vertex/pixel position into light space and then into texture space??

I have in the vertex shader:

output.LightPosition = mul(input.Position, lightWorldViewProj);

output.LightPosition /= output.LightPosition.w;

And in the pixel shader:

float2 projectedTexCoords;

projectedTexCoords[0] = input.LightPosition.x / 2.0f + 0.5f;

projectedTexCoords[1] = input.LightPosition.y / -2.0f + 0.5f;

float shadowMapDepth = shadowMap.Sample(shadowMapSampler, projectedTexCoords).r;

float realDistance = input.LightPosition.z;

if ((realDistance - 1.0f / 100.0f) <= shadowMapDepth)

{

colour *= 0.25;

}

return colour;

I 'm using a left handed co-ord system.

I added a screenshot. The sun is 25deg above the east (x axis) and looking at the origin.

The camera is looking west or in the -x direction. There should not be that much shadow.

The greyscale image in the corner is the heightmap.

I only have terrain. I want to get the self shadowing working. I used code from tutes, so I assumed it would work.

I've looked at tutes on http://www.riemers.net and http://takinginitiative.net/2011/05/15/directx10-tutorial-10-shadow-mapping/