WanImageMotionPro Plus

When IAMCCS shipped the SVI Pro v2 motion nodes in March 2026, one r/comfyui thread put it better than any README could: "Wan 2.2 is still incredible - huge thanks to IAMCCS-Nodes for SVI Pro v2," with the author running native 1728x960 on a 16GB RTX 5070 Ti. WanImageMotionPro is the node from that post - the thing that made long, planned Wan 2.2 takes practical, and the one node in this pack I'd reach for first.

What it is

It's a conditioning-and-latent builder, not a sampler and not a model: feed it the pieces of an I2V segment and it hands back conditioning plus an empty latent ready for a Wan sampler. Over stock WanImageToVideo-style nodes it adds three things bolted together:

1. Motion amplitude control - a motion boost (default 1.15) applied to the carried-over motion tail, fixing the slow-motion/stiff feel people hit in SVI Pro pipelines.
2. FLF start lock - lock_start_slots (1) hard-locks the first latent slots to anchor_samples via a concat mask, so the clip genuinely starts from your reference image.
3. FLF end lock - end_lock_slots (1) hard-locks the last latent slots to end_samples, so the clip lands on your chosen end frame.

That start-and-end anchoring is the "first/last frame" thing SVI alone couldn't do, and it's what turns an emergent 20-second drift into a shot you can actually plan.

The inputs that matter

• positive / negative - your conditioning, typically from a WAN text encoder.
• anchor_samples - the encoded start image(s); length (81) is visible frames (Wan latents run 4 frames per slot).
• motion (1.15) and motion_mode - motion_only (prev_samples) boosts just the carried tail; all_nonfirst boosts everything after the first slot. Default is fine to start.
• safety_preset - safe (default) does per-channel stabilization + a tanh limiter + a 2-frame ramp at any motion value. safer tightens it above ~1.5; base is 1:1 with the original SVI Pro FLF node; legacy mirrors PainterI2V. Start on safe.
• use_end_frame + end_samples - flip the toggle true and connect an end-frame latent for the end lock; leave it false and end_samples is ignored even if wired (the documented way to dodge ping-pong artifacts).
• end_lock_slots (1) - final slots locked to the end frame (1 ≈ the last ~4 video frames; 16 = 1:1 parity with the original FLF node). lock_start_slots (1) does the same for the start; 0 lets motion start at frame one.
• end_overshoot_slots (0) - extends the generation window past the visible clip so the clip converges toward the end frame instead of hard-freezing on it. Recommended for clean FLF endings; trim_slots output says how much to cut afterward.
• latent_refresh (0) - per-channel mean/contrast matching between the motion tail and the anchor, fighting SVI's drift and color shift. Start at 0.5 for chains of 3+ segments.
• clip_vision_mode (auto) - how start/end CLIP-Vision embeddings merge: auto (concat) suits true A→B transitions; end_only suits SVI continuation where anchor and end are the same image but prev_samples came from another scene.
• vram_profile - normal through loop_per_frame (lowest_vram) and cpu_offload (slowest); your 16GB-and-below lever. Optional prev_samples (previous generation's latents) and clip_vision_start_image/clip_vision_end_image.

Outputs: positive, negative, the built latent, and trim_slots - wire that into WanMotionProTrimmer after sampling.

How it works

It concatenates the anchor and motion-tail latents and sets a 4-channel concat mask marking which slots are locked and which are generation targets; the end lock overwrites the final slots with end_samples and masks them the same way. The motion stage scales the tail before conditioning, and the safety presets wrap that with limiters and ramps so a big motion value doesn't blow out colors or melt seams. All latent-space math, no new weights - which is why the node itself has nothing to download.

Installing it

Ships in IAMCCS-nodes - ComfyUI Manager (search "IAMCCS"), or:

cd ComfyUI/custom_nodes
git clone https://github.com/IAMCCS/IAMCCS-nodes.git

Restart after. The node carries no weights, but the pipeline it feeds needs the SVI Pro LoRAs (the HIGH/LOW pair from Kijai's WanVideo_comfy) on a Wan 2.2 I2V model. Keep the pack updated - CCS ships constantly and this node has been through several behavior revisions.

Common issues

• end_transition_frames is deprecated - leave it at 0. Values above 0 blend padding latents toward the end frame in latent space, and VAE latent interpolation isn't linear, so you get static/frozen output. 0 is the hard cut matching the original FLF behavior.
• Overshoot + KJNodes crash. end_overshoot_slots > 0 has been reported to crash with an einops shape mismatch when KJNodes WAN attention optimizations (FETA / wrapped_attention) are enabled. Set overshoot to 0 or update/disable that KJNodes option.
• "Static clip" or segment jumps. Flip diagnostic_log on - it prints the concat-latent/mask and motion/end-lock ranges so you can see what the node actually built.
• Color shift near the end of a stage was the top community complaint on the release thread. That's what latent_refresh plus end_only clip-vision routing fix; 0.5 refresh with end_only on continuation segments is a solid starting point.