ComfyUI-SAM3D-BodyMod

ComfyUI-SAM3D-BodyMod

Custom nodes for estimating, stylizing, and transferring MHR body shapes, plus camera-orbit control for native ComfyUI SAM3D Body pose data.

The pack uses ComfyUI's native SAM3D_BODY_MODEL and MHR_POSE_DATA types. It does not modify the SAM3D checkpoint or add another model dependency.

Nodes

Detect SAM3D Body Shape

Runs the native SAM3D Body predictor on one or more reference images, aggregates the selected person's 45 shape and 28 scale coefficients, and optionally refines them against the reference silhouette.

Outputs:

• shape_profile: reusable SAM3D_BODY_SHAPE_PROFILE
• fitted_reference_pose: regenerated MHR_POSE_DATA for previewing with the native Render 3D Body Pose node

Detection presets:

• real_human: keeps fitting close to SAM3D's learned realistic-human estimate.
• cartoon: permits larger silhouette-driven coefficient changes.

fit_strength controls only the silhouette correction. recognition_exaggeration scales all detected deviations from MHR's mean shape and mean proportions: 1 preserves the estimate, values above 1 exaggerate it, and 0 returns to the mean coefficients.

Connect a clean foreground mask when possible. mask_polarity=auto accepts both ordinary white-subject masks and the inverted alpha mask produced by ComfyUI's Load Image node. Without a mask, the node estimates the background color from the image border.

SAM3D Body Type Preset

Stylizes an existing shape profile before it is applied to animation:

• detected: leaves the profile unchanged.
• ectomorph: projects a slimmer, longer visual target into the MHR identity basis.
• mesomorph: emphasizes upper torso, shoulders, and thighs with a narrower waist.
• endomorph: emphasizes abdomen and hip volume.
• maximize_detected: amplifies all detected shape and proportion coefficients.

The named body types are artistic controls, not physiological or medical classifications. They do not rely on guessed PCA component meanings: the node constructs a geometric target on MHR's canonical body and projects it into the model's actual 45-component identity basis. strength=0 is unchanged; higher values increase the effect.

Apply SAM3D Body Shape

Applies the profile to animated MHR_POSE_DATA. Surface identity and skeletal proportions have independent strengths. The node re-runs MHR and updates vertices, 2D/3D keypoints, joint positions and rotations, face landmarks, camera translation, and packed model parameters.

Anchoring options:

• camera: preserve the original camera translation.
• pelvis: keep the pelvis fixed in camera space; recommended for most animation drivers.
• feet: keep the average ankle position fixed; useful when floor contact matters most.

Drive SAM3D Body Camera

Orbits the camera around every frame of MHR_POSE_DATA, then reprojects the native mesh, body/face keypoints, and joints. Connect its output to Render 3D Body Pose.

Static controls are azimuth, elevation, distance, and optional vertical fov. The built-in camera handle supports:

• left-drag the camera marker to set azimuth/elevation;
• drag empty space to rotate the editor view;
• use the mouse wheel to dolly;
• right-click the sphere to add a keyframe or right-click a marker to remove it;
• left-drag a keyframe marker to change its angle and hover-scroll it to change its distance;
• double-click to reset the editor view.

Set frame_count to the pose sequence length before placing keyframes. The first right-click captures the current static camera and adds the new camera position. Two keyframes enable use_keyframes. Frame numbers are 1-based and stored in the editable keyframes JSON field. linear paths use straight segments; smooth uses Catmull-Rom interpolation through three or more markers. Azimuth interpolation follows the shortest route across the ±180-degree seam.

The camera node materializes the selected view into camera-space pose geometry. Put it af