Fix broken backward graph when using `LieTensor.exp()`

facebookresearch / theseus

A library for differentiable nonlinear optimization

MIT License

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Fix broken backward graph when using `LieTensor.exp()` #631

Closed luisenp closed 9 months ago

luisenp commented 9 months ago

Closes #626

luisenp commented 9 months ago

@fantaosha The reason is that the standard LieTensor constructor is not a differentiable operation. If you want to make a new LieTensor in a differentiable way (e.g., as the result of an exp map), you need a tensor creation function that has a backward implementation. This is already available in FromTensor class, I just forgot to use it inside the exp map function.