I know, there are some similar topics, but I don't understand the solution. I made the CSM based on this paper: http://developer.download.nvidia.com/SDK/10.5/opengl/src/cascaded_shadow_maps/doc/cascaded_shadow_maps.pdf
with some "improvements". Here is the code:
I have a matrix which is used when I create the shadows
float texOffset = 0.5f + (0.5f / (float)shadowSize);
float bias = 0.003f;
textureMat = Matrix(0.5f, 0.0f, 0.0f, 0.0f,
0.0f, -0.5f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f, 0.0f,
texOffset, texOffset, -bias, 1.0f);
Now, here is the frustum corner's computing:
void Shadow::ComputeFrustumCorners()
{
float& camAspect = scene->camera->aspect;
Vector3& camEye = scene->camera->eyePosition;
Vector3 dir;
dir.x = scene->camera->GetView().m[0][2];
dir.y = scene->camera->GetView().m[1][2];
dir.z = scene->camera->GetView().m[2][2];
Vector3 x;
x.x = scene->camera->GetView().m[0][0];
x.y = scene->camera->GetView().m[1][0];
x.z = scene->camera->GetView().m[2][0];
Vector3 y;
y.x = scene->camera->GetView().m[0][1];
y.y = scene->camera->GetView().m[1][1];
y.z = scene->camera->GetView().m[2][1];
tanHalfFov = tanf(scene->camera->fov * 0.5f);
float nPlaneH = tanHalfFov * nearPlane;
float nPlaneW = nPlaneH * camAspect;
float fPlaneH = tanHalfFov * farPlane;
float fPlaneW = fPlaneH * camAspect;
Vector3 nPlaneX = x * nPlaneW;
Vector3 nPlaneY = y * nPlaneH;
Vector3 fPlaneX = x * fPlaneW;
Vector3 fPlaneY = y * fPlaneH;
nPlaneCenter = camEye + dir * nearPlane;
fPlaneCenter = camEye + dir * farPlane;
frustumCorners[0] = nPlaneCenter - nPlaneX - nPlaneY;
frustumCorners[1] = nPlaneCenter - nPlaneX + nPlaneY;
frustumCorners[2] = nPlaneCenter + nPlaneX + nPlaneY;
frustumCorners[3] = nPlaneCenter + nPlaneX - nPlaneY;
frustumCorners[4] = fPlaneCenter - fPlaneX - fPlaneY;
frustumCorners[5] = fPlaneCenter - fPlaneX + fPlaneY;
frustumCorners[6] = fPlaneCenter + fPlaneX + fPlaneY;
frustumCorners[7] = fPlaneCenter + fPlaneX - fPlaneY;
}
I get the x,y,z axes from the view matrix, so I don't have to compute these values.
And of course the "main part" of CSM; compute the viewproj matrix for the shadow map generation, and the "final matrix" for the "final" shadow rendering. I think I should modify this part to kill the swimming edges.
void Shadow::ComputeMatrices()
{
ComputeFrustumCorners();
view = Matrix::LookAt(Vector3::Zero, light->direction, Vector3::Up);
Vector3 min = Vector3::Max;
Vector3 max = Vector3::Min;
Vector4 transformed;
for (int i = 0; i < NUM_CORNERS; i++)
{
transformed = Vector4::Transform(frustumCorners, view);
transformed /= transformed.w;
if (transformed.x < min.x)
min.x = transformed.x;
if (transformed.y < min.y)
min.y = transformed.y;
if (transformed.z < min.z)
min.z = transformed.z;
if (transformed.x > max.x)
max.x = transformed.x;
if (transformed.y > max.y)
max.y = transformed.y;
if (transformed.z > max.z)
max.z = transformed.z;
}
float scaleX = 2.0f / (max.x - min.x);
float scaleY = 2.0f / (max.y - min.y);
float offsetX = -0.5f * (min.x + max.x) * scaleX;
float offsetY = -0.5f * (min.y + max.y) * scaleY;
cropMat.m[0][0] = scaleX;
cropMat.m[1][1] = scaleY;
cropMat.m[2][2] = 1.0f;
cropMat.m[3][0] = offsetX;
cropMat.m[3][1] = offsetY;
cropMat.m[3][3] = 1.0f;
// INFO: bias
float bias = 10.0f;
min.z -= bias;
max.z += bias;
proj = Matrix::OrthographicOffCenter(-1, 1, -1, 1, min.z, max.z);
viewProj = view * proj * cropMat;
finalMat = viewProj * textureMat;
}
So the problem is that, when I move or rotate the camera (not the light), the shadow edges are swimming / flickering. What is the solution for my code?
Thanks for all replies!
), but the character (the player) moves together with the camera, and its shadow is still flickering.
Thanks for your help!
