Confusing loop variable naming in backward::renderCUDA

[ringohoffman]

diff-gaussian-rasterization/cuda_rasterizer/backward.cu

Lines 476 to 477 in 59f5f77

	for (int i = 0; i < C; i++)
	collected_colors[i * BLOCK_SIZE + block.thread_rank()] = colors[coll_id * C + i];

	for (int i = 0; i < rounds; i++, toDo -= BLOCK_SIZE)
	{
		...
			for (int i = 0; i < C; i++)  // <--
				collected_colors[i * BLOCK_SIZE + block.thread_rank()] = colors[coll_id * C + i];

i is being used for the inner and outer loop here. Is it intended exactly as it is written? I think it could be good to change i to ch like in the other loops in this outer loop to avoid confusion.

[ringohoffman]

This one looks to be as intended but it would probably be good to change this one too:

diff-gaussian-rasterization/cuda_rasterizer/backward.cu

Lines 532 to 533 in 59f5f77

	for (int i = 0; i < C; i++)
	bg_dot_dpixel += bg_color[i] * dL_dpixel[i];