Class: Gsplat::Ops::QuatScaleToCovarPreci

Inherits:
Autograd::Function show all
Defined in:
lib/gsplat/ops/quat_scale_to_covar_preci.rb

Overview

Differentiable conversion from wxyz quaternions/scales to covariance and precision.

Class Method Summary collapse

Class Method Details

.apply(quaternions, scales, compute_covar: true, compute_preci: true, triu: false) ⇒ Array<(Autograd::Variable, nil)>

Applies the operation while retaining Python gsplat's two tuple positions.

Parameters:

  • quaternions (Autograd::Variable, Numo::NArray) —

    [...,4]

  • scales (Autograd::Variable, Numo::NArray) —

    [...,3]

  • compute_covar (Boolean) (defaults to: true)
  • compute_preci (Boolean) (defaults to: true)
  • triu (Boolean) (defaults to: false) —

    return [...,6] upper triangles when true

Returns:



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# File 'lib/gsplat/ops/quat_scale_to_covar_preci.rb', line 19

def apply(quaternions, scales, compute_covar: true, compute_preci: true, triu: false)
  validate_selection!(compute_covar, compute_preci)
  outputs = super
  return outputs if compute_covar && compute_preci
  return [outputs, nil] if compute_covar

  [nil, outputs]
end

.backward(context, *grad_outputs) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Propagates matrix gradients to quaternions and scales.



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# File 'lib/gsplat/ops/quat_scale_to_covar_preci.rb', line 50

def backward(context, *grad_outputs)
  quaternions, scales, compute_covar, compute_preci, triu = context.saved_values
  grad_covar = compute_covar ? grad_outputs.shift : nil
  grad_preci = compute_preci ? grad_outputs.shift : nil
  Backend.dispatch(
    :quat_scale_to_covar_preci_backward,
    quaternions,
    scales,
    grad_covar,
    grad_preci,
    triu: triu
  )
end

.forward(context, quaternions, scales, **options) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Evaluates covariance/precision tensors and records inputs for VJP.



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# File 'lib/gsplat/ops/quat_scale_to_covar_preci.rb', line 30

def forward(context, quaternions, scales, **options)
  compute_covar = options.fetch(:compute_covar)
  compute_preci = options.fetch(:compute_preci)
  triu = options.fetch(:triu)
  context.save(quaternions, scales, compute_covar, compute_preci, triu)
  covariance, precision = Backend.dispatch(
    :quat_scale_to_covar_preci_forward,
    quaternions,
    scales,
    compute_covar: compute_covar,
    compute_preci: compute_preci,
    triu: triu
  )
  return [covariance, precision] if compute_covar && compute_preci

  compute_covar ? covariance : precision
end