I’m making a procedurally generated terrain using a MeshDescription:
void ATerrain::createTerrainMesh() {
//Describes the mesh to create
FMeshDescription terrainDescriptor;
FStaticMeshAttributes attributes(terrainDescriptor);
attributes.Register();
//creates static mesh
UStaticMesh *terrain = NewObject<UStaticMesh>(this, FName(TEXT("ProceduralStaticMesh")));
//the class that builds the mesh
FMeshDescriptionBuilder meshDescBuilder;
meshDescBuilder.SetMeshDescription(&terrainDescriptor);
meshDescBuilder.EnablePolyGroups();
meshDescBuilder.SetNumUVLayers(1);
// Array to store all the vertices
TArray< FVertexInstanceID > vertexInsts;
TArray< FVertexID > vertexIDs; vertexIDs.SetNum(vertexNum*vertexNum);
float dist = terrainSize / vertexNum; //distance between each vertex
// Create vertices
for (int i = 0; i < vertexNum; i++) { //x
for (int j = 0; j < vertexNum; j++) { //y
vertexIDs[cti(i,j)] = meshDescBuilder.AppendVertex(FVector(dist * i, dist * j, getVertexHeight(i,j)));
}
}
//add istances
FVertexInstanceID instance;
for (int i = 0; i < vertexNum; i++) { //x
for (int j = 0; j < vertexNum; j++) { //y
instance = meshDescBuilder.AppendInstance(vertexIDs[cti(i, j)]);
meshDescBuilder.SetInstanceNormal(instance, FVector(0, 0,1));
meshDescBuilder.SetInstanceUV(instance, FVector2D((uvScale/ (vertexNum - 1))*i, (uvScale/ (vertexNum - 1))*j), 0 );
meshDescBuilder.SetInstanceColor(instance, FVector4(1.0f, 1.0f, 1.0f, 1.0f));
//meshDescBuilder.SetAllEdgesHardness(true);
vertexInsts.Add(instance);
}
}
//create triangles
FPolygonGroupID polygonGroup = meshDescBuilder.AppendPolygonGroup();
for (int i = 0; i < vertexNum - 1; i++) { //x
for (int j = 0; j < vertexNum - 1; j++) { //y
meshDescBuilder.AppendTriangle(vertexInsts[cti(i, j+1)], vertexInsts[cti(i+1, j)], vertexInsts[cti(i, j)], polygonGroup);
meshDescBuilder.AppendTriangle(vertexInsts[cti(i, j + 1)], vertexInsts[cti(i + 1, j + 1)], vertexInsts[cti(i+1, j)], polygonGroup);
}
}
// Build static mesh
TArray<const FMeshDescription*> meshDescPtrs;
meshDescPtrs.Emplace(&terrainDescriptor);
terrain->BuildFromMeshDescriptions(meshDescPtrs, false);
mesh->SetStaticMesh(terrain);
mesh->bDrawMeshCollisionIfComplex = true;
mesh->SetCollisionObjectType(ECollisionChannel::ECC_WorldStatic);
mesh->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
mesh->bUseDefaultCollision = true;
mesh->SetCollisionResponseToChannel(ECollisionChannel::ECC_Pawn, ECollisionResponse::ECR_Block);
mesh->SetSimulatePhysics(true);
mesh->SetEnableGravity(false);
}
I don’t undestand why this is not working. Because I set bDrawMeshCollisionIfComplex to true when I run the game I can see some cyan lines indicating the collision. When in the editor I go into “view player collision mode” the terrain colors purple, everything is hinting at the collision being there but it doesn’t work.
First I tried with my player controller then I placed a cube with physics and they both fell through the terrain.