From 193fdc276a43ad94a961aa9214be27cfa879d225 Mon Sep 17 00:00:00 2001 From: skal Date: Mon, 23 Mar 2026 08:07:31 +0100 Subject: docs: update temporal feedback docs — wire_dag auto-wiring, F16X8 format MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - HOWTO.md: replace manual set_cnn_output_node() instructions with wire_dag() auto-wiring explanation; add timeline.seq snippet as canonical wiring example; document F16X8/GBUF_ALBEDO format requirement - CNN_V3.md: fix prev_tex format (rgba16float, not rgba8unorm); mark timeline.seq CNNv3Effect TODO as done - SEQUENCE.md: already updated in previous commit (wire_dag pattern, format-matching rule, sink guard) Co-Authored-By: Claude Sonnet 4.6 --- cnn_v3/docs/HOWTO.md | 48 ++++++++++++++++++++++++++++-------------------- 1 file changed, 28 insertions(+), 20 deletions(-) (limited to 'cnn_v3/docs/HOWTO.md') diff --git a/cnn_v3/docs/HOWTO.md b/cnn_v3/docs/HOWTO.md index 48b5d68..5cfc371 100644 --- a/cnn_v3/docs/HOWTO.md +++ b/cnn_v3/docs/HOWTO.md @@ -95,20 +95,32 @@ outputs[1] → feat_tex1 (rgba32uint: mat_id, prev.rgb, mip1.rgb, mip2.rgb, d ### Temporal feedback (prev.rgb) -`GBufferEffect` owns a persistent internal node `_prev` (rgba8unorm, `U8X4_NORM`). -Each frame it is GPU-copied from the CNN effect's output before Pass 1 runs, then bound as -`prev_cnn` in the pack shader (binding 6). +`GBufferEffect` owns a persistent internal node `_prev` (`F16X8` = Rgba16Float, +`CopySrc|CopyDst`). Each frame it is GPU-copied from the CNN effect's output after all +effects render (`post_render`), then bound as `prev_cnn` in the pack shader (binding 6). -**To wire temporal feedback**, call once after constructing the effects: -```cpp -gbuf->set_cnn_output_node("cnn_v3_out"); // name of CNNv3Effect's output node +**Wiring is automatic** via `wire_dag()`, called by `Sequence::init_effect_nodes()`. +`GBufferEffect` scans the DAG for the first downstream consumer of its output nodes and +uses that effect's output as `cnn_output_node_`. No manual call needed. + +**Requirement**: the sequence must include `CNNv3Effect` downstream of `GBufferEffect`. +In `timeline.seq`, declare a `gbuf_albedo` output node and add the effect: + +```seq +NODE cnn_out gbuf_albedo +EFFECT + GBufferEffect source -> gbuf_feat0 gbuf_feat1 0 60 +EFFECT + CNNv3Effect gbuf_feat0 gbuf_feat1 -> cnn_out 0 60 ``` +If no CNN effect follows, `cnn_output_node_` stays empty and `post_render` is a no-op +(prev.rgb will be zero — correct for static/debug-only sequences). + Frame 0 behaviour: `_prev` is zeroed on allocation → `prev.rgb = 0`, matching the training convention (static frames use zero history). The copy uses `wgpuCommandEncoderCopyTextureToTexture` (no extra render pass overhead). -Both textures must be `rgba8unorm` — the CNN output sink (`U8X4_NORM`) satisfies this. +`node_prev_tex_` is `F16X8` (Rgba16Float) to match the `GBUF_ALBEDO` format of CNNv3Effect's +output — `CopyTextureToTexture` requires identical formats. --- @@ -320,10 +332,7 @@ SEQUENCE 0 0 "Scene with CNN v3" EFFECT + CNNv3Effect gbuf_feat0 gbuf_feat1 -> sink 0 60 ``` -After constructing the effects, wire temporal feedback: -```cpp -gbuf_effect->set_cnn_output_node("sink"); // or whichever node receives CNN output -``` +Temporal feedback is wired automatically by `wire_dag()` — no manual call needed. FiLM parameters uploaded each frame: ```cpp @@ -477,16 +486,15 @@ GBufViewEffect(const GpuContext& ctx, float start_time, float end_time) ``` -**Wiring example** (alongside GBufferEffect): +**Wiring example** — use `timeline.seq`, temporal feedback wires automatically: -```cpp -auto gbuf = std::make_shared(ctx, - std::vector{}, // no external inputs - std::vector{"gbuf_feat0", "gbuf_feat1"}, 0.0f, 60.0f); -gbuf->set_cnn_output_node("cnn_out"); // wire temporal feedback after CNN is constructed -auto gview = std::make_shared(ctx, - std::vector{"gbuf_feat0", "gbuf_feat1"}, - std::vector{"gbuf_view_out"}, 0.0f, 60.0f); +```seq +NODE gbuf_feat0 gbuf_rgba32uint +NODE gbuf_feat1 gbuf_rgba32uint +NODE cnn_out gbuf_albedo +EFFECT + GBufferEffect source -> gbuf_feat0 gbuf_feat1 0 60 +EFFECT + CNNv3Effect gbuf_feat0 gbuf_feat1 -> cnn_out 0 60 +EFFECT + GBufViewEffect gbuf_feat0 gbuf_feat1 -> sink 0 60 ``` **Grid layout** (output resolution = input resolution, channel cells each 1/4 W × 1/5 H): -- cgit v1.2.3