Applying material on terrain mesh from OmnilsaacGymEnvs


I am building an extension that generate rough terrain environment in isaac sim. I generate vertices and faces using the source code provided by omniIsaacGymEnvs:

Once the meshes are imported into the stage and can be visualize through the viewport, I want to apply a material texture such as grass for instance. So far I am doing it manually via the GUI but the rendering does not appear. Below is an video example that shows the problem:

You will see that the terrain meshes generated through python api do not change when a texture is applied whereas a plane mesh created form the GUI displays the right texture.
Here is code below that consist of 3 files:,, (8.1 KB)


Hi there, thanks for reporting this. I suspect this is because the generated terrain mesh is missing the normals attributes. We will take a further look at this issue internally.

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I implemented the vertices normals with the following functions:

def compute_face_normals(faces, vertices):
    n_F = faces.shape[0]  
    face_normals = np.zeros((n_F, 3))
    for i in range(n_F):
        a = faces[i, 0]
        b = faces[i, 1]
        c = faces[i, 2]

        A = vertices[a, :]
        B = vertices[b, :]
        C = vertices[c, :]

        BA = B - A
        CA = C - A

        face_normal = np.cross(BA, CA)

        face_normal /= np.linalg.norm(face_normal)

        face_normals[i, :] = face_normal
    return face_normals
def compute_vertex_normals(faces, vertices):
    n_V = vertices.shape[0]
    vertex_normals = np.zeros((n_V, 3))

    # Compute face normals
    face_normals = compute_face_normals(vertices, faces)

    # Accumulate face normals for each vertex
    for i in range(faces.shape[0]):
        a = faces[i, 0]
        b = faces[i, 1]
        c = faces[i, 2]

        vertex_normals[a, :] += face_normals[i, :]
        vertex_normals[b, :] += face_normals[i, :]
        vertex_normals[c, :] += face_normals[i, :]

    # Normalize vertex normals
    vertex_normals /= np.linalg.norm(vertex_normals, axis=1)[:, np.newaxis]

    return vertex_normals

But the meshes still do not show the right texture when a material is assigned to them.

Hi @kellyg - Any news from your side?


Hi @yohan.legars - This will be fixed in the future Isaac Sim release (Expected around June month)

1 Like

Hi there,

The UVW coordinates needed to be enabled.

Problem solved !!!

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