Respource duplication in new pipelined rendering

[vtimonin]

I briefly checked new pipelined rendering and it seems RenderStage::Extract stage clones all heavy resources such as Images or Meshes. This looks very wasteful...

[DJMcNab]

We've discussed this before on discord, and iirc, it was only adding the new items based on the events.

See e.g.
https://discord.com/channels/691052431525675048/743663924229963868/891477293506117642

[vtimonin]

Yes, resource extraction is performed only for changed resources, that is fine. But the render world stores copies of such resources. I can be wrong and probably e.g. images are removed from CPU memory after corresponding GPU buffers are created - it should be fine in this case.
Otherwise it can practically double used RAM.

[DJMcNab]

However, they get drained from the extracted assets here:

bevy/pipelined/bevy_render2/src/render_asset.rs

Line 143 in 43e8a15

for (handle, extracted_asset) in std::mem::take(&mut extracted_assets.extracted) {

[vtimonin]

Yes, prepare_assets consumes assets, so it seems to be ok.

[DJMcNab]

If you're satisfied (and it's possible to do so), would you be able to move this to the Q&A category and mark an answer?

Otherwise, we might need @cart to move it - he might be the only one with permission.

Also, in future please reply within a thread rather than creating a new thread for each comment.