Start and End Frames: How to Control the Motion in Your Video

With one start image, you hand the model the beginning and let it decide the rest. That is great for exploration. But sometimes you know where the clip should end up: the character should be facing the camera, the door should be open, the pose should match another illustration. For that, you need to control the ending too.

In WaifuRush, Nsfw video pro does exactly this. You can supply a start image, an end image, or both, plus an optional short idea, and choose a duration of 5, 8, 10 or 15 seconds.

The three ways to use Nsfw video pro

Start image only

The video begins on your image and the model animates forward. It is the same idea as basic image-to-video, but with a choice of duration and an optional idea about what should happen. Use it when you care about the opening and are happy to be surprised by the rest.

End image only

The video arrives at your image. This is useful when you have a finished final pose, such as a reveal, but no particular start. The model works backwards in the sense that the clip must land on your picture.

Start and end images

The clip moves from one image to the other. This is the most controlled option: you define both anchors and the model fills in the motion between them. It is the closest thing to keyframe animation that you can do without drawing the in-between frames.

The studio requires at least one of the two images. If you add neither, it asks you to add a start or an end image first.

Planning two frames that work together

The model is good at smooth change between frames that belong together, and poor at jumps between frames that do not. Plan the pair deliberately.

• Keep the character, outfit and art style identical in both images. If the two look like different drawings, the model has to blend them mid-clip, and you will see a transformation instead of a movement.
• Keep the background consistent unless the clip is meant to move through space. A camera move from one place to another is a bigger ask than a character changing pose.
• Make the change between frames something a person could do in a few seconds: turning the head, lifting an arm, stepping forward, opening the eyes.
• Use the same aspect ratio for both images. The output follows the image ratio, so matching frames avoid confusion.

A reliable way to make a matching pair is to start from one illustration and create the second as a small edit of it: the same drawing with a changed pose or expression. If you work digitally, duplicate the layer file and change only what should differ.

Choosing a duration

The available durations are 5, 8, 10 and 15 seconds. Longer clips cost more credits and give the model more time in which small errors accumulate, so choose the shortest length that tells your story.

• 5 seconds: a single gesture or expression change. Best default for first tries.
• 8 seconds: a gesture with a bit of lead-in and settle.
• 10 seconds: a two-part movement, such as turning and then smiling.
• 15 seconds: a longer beat. Use it when the two frames are far apart or the story needs time. For anything longer than this, consider building the scene in pieces with the director mode.

Writing the optional idea

You never write the full model prompt in WaifuRush. The site reads your images and writes it. In the pro mode you can add a short idea of your own, and the site builds on it. Because the frames already define the destination, the idea should describe the manner of the movement, not the destination itself.

Compare:

• Less useful: "A girl with long silver hair wearing a blue coat in a snowy street turns around." The images already show all of this.
• More useful: "She turns slowly and looks back over her shoulder." It specifies speed and manner.

Keep it to one sentence, in plain language, and describe physical movement. If you leave it empty, the site will still write a prompt from the images alone, which is a good baseline to compare your ideas against.

Step-by-step: a start and end clip

1. Prepare two matching images with the same character and style, and the change you want between them.
2. Open the studio and select Nsfw video pro.
3. Add the start image and the end image.
4. Choose a duration. Start with 5 seconds if the change is small.
5. Choose Fast quality for a first try. It is the lighter option, and 480p trims the price a little further.
6. Add a short idea about the manner of movement, or leave it blank.
7. Press Create, and review the result. Is the transition smooth? Does it land on the end image cleanly?
8. Adjust one thing at a time: the idea, the duration, or the end image. Re-render at 720p when you are happy.

Troubleshooting

The middle of the clip looks like a morph

Your two frames are probably too different. Reduce the change between them, or fix inconsistencies (color, outfit details, background) so they read as the same scene.

The character changes appearance halfway

Try a shorter duration and make sure the face is clear and similar in both images. A blurry face in the end image invites a different face.

The movement is too slow or too fast

Duration sets the pace for a given change. Move from 5 to 8 seconds for a slower, more relaxed version, or from 10 to 5 for a snappier one. Your idea can also say "slowly" or "quickly".

The ending is not exactly my image

The model aims for your end image but produces a video, so expect close rather than pixel-identical. If precision matters, check the last frames and trim or pick the best frame in your video editor.

When one image is enough

Two frames add control but also add work. If you simply want your art to come alive, the loop mode or a start-only clip is faster. Reach for start and end frames when the destination matters: a reveal, a matching pose, a transition between two illustrations, or a hand-off to another clip.