three-d: FailedToFindUniform error

In bd52faca, I get a the following error from examples/mandelbrot

thread ‘main’ panicked at ‘called Result::unwrap() on an Err value: FailedToFindUniform { message: “Failed to find uniform normalMatrix” }’, examples/mandelbrot/main.rs:55:75

and this from examples/statues

thread ‘main’ panicked at ‘called Result::unwrap() on an Err value: FailedToFindUniform { message: “Failed to find uniform normalMatrix” }’, examples/statues/main.rs:58:12

I’m also getting something similar in my own project code, as I’m replacing the phong renderer with code based on Mesh::render. I tried to look for a cause and I haven’t found one yet; hopefully the cause is recognizable.