Adding Blob Shadows to Models

From C4 Engine Wiki

Make a texture of the blob shadow. For every frame, create a MarkingEffect object at the model's position with a normal of (0,0,1) and a tangent pointing to the model's right. Use the MarkingEffect::New() function to add the marking data:

MarkingData    data;
 
data.center = model->GetWorldPosition();        // Bottom center of model
data.normal.Set(0.0F, 0.0F, 1.0F);              // Up direction
data.tangent = model->GetWorldTransform()[0];   // Right direction
data.radius = 0.25F;                            // Change to whatever you need
data.textureName = "MyTexture";                 // Change to blob texture's name
data.color.Set(0.0F, 0.0F, 0.0F, 1.0F);         // Black shadow
data.lifeTime = -1;                             // Marking only survives one frame
 
MarkingEffect::New(model->GetWorld()->GetRootNode(), &data);

Use this code in the model controller's Move() function. This code will cause a new marking to appear at the model's base every frame.

Note that making a blob shadow with this method performs a full geometric clip every frame. It seems to be very fast, but if the geometry beneath a model's base is very complicated, or blobs are being created for a lot of models, there could be performance consequences.

Turn on wire frame (see Using the Command Console) and switch to the third-person camera to see how the engine creates the effect and forms it to the underlying geometry.