Freelance projects

Freelance projects

3D model of a "banana" bag with a die-cut handle

3D Modeling — incorrectly specified categories?

Project translated automatically. Log in or register, to view the original

Task: 3D model of a "banana" bag with a die-cut handle (for interactive mockup)

1. Purpose

A parametric 3D model of a polyethylene "banana" bag with a die-cut handle. The model will be used in a web viewer (Three.js / glTF) for an interactive mockup: the client's print layout is applied to it, the user rotates the bag and approves the design. This is not a render asset for a single beautiful image, but a flexible model that the program changes according to parameters. Therefore, the key requirement is clean, even, deformable geometry, not a baked shape.

2. Product Design

The bag consists of two panels: FRONT (front) and BACK (back), welded on the sides.
Between them at the bottom is a bottom gusset (fold), which opens up so that the bag can stand. In the folded (flat) state, the gusset = 0.
Handle — a die-cut hole in the shape of a stadium (rounded rectangle) at the top edge. The holes on the front and back are aligned (they match when holding the bag).
At the neck, there is a thin reinforcing hem (double layer of film), as on the real sample (see reference photo). If the specific product does not have it — clarify, but by default we include it.

The reference (base) size for construction: width 300 mm × height of panel 400 mm × gusset 50 mm (as shown in the unfolding drawing in references).

3. Parameters that should change

The model is built once in the base size but should behave correctly when changing the following:

Dimensions (width / height). Scaling is done programmatically by us. The model requires uniform topology (see §4), so that there are no artifacts and creases with uneven scaling. IMPORTANT: the handle is excluded from scaling — see §5. The walls stretch, the handle remains rigid (fixed size and fixed offset from the top edge).
Depth of the gusset: from 0 (flat bottom) to maximum. Implemented through shape key (morph): "gusset closed → gusset opened". 0 = flat bag, without a separate model.
Filling volume: from almost flat to moderately filled. Also shape key: "flat → softly filled". The degree is adjustable by us. The volume is moderate (the edges slightly bulge, slight sagging), not a "balloon" — otherwise, when changing sizes, the shape will distort.
Shape of the handle: two contour presets — straight stadium and curved ("banana", like a smile). It is preferable to implement a shape key for the contour morph (straight ↔ curved). If the contour morph gives a dirty mesh — it is acceptable to provide two mesh variants of one model (everything else is identical, only the handle contour differs). The choice is yours based on the cleanliness of the result.

4. Topology / Mesh (critical)

Only quads, no n-gons and no triangles (except for the inevitable ones at the rounded handle).
Uniform, even mesh across the panels — so that the bag can be scaled and deformed without creases and pinched polygons.
The handle area is topologically separated: around the die-cut hole — a separate closed edge loop, separating the "rigid" part of the handle from the stretching wall. This is necessary so that when scaling the bag, the handle area can be excluded from stretching and maintain its real size and position. The transition between the rigid handle area and the stretching wall is clean, without elongated polygons.
NO baked folds, wrinkles, drapery in the geometry. The surface is calm and clean. A slight softness of the shape is set by the volume (§3.3) and then by the material during rendering, not sculpted in the mesh.
The mesh is subdivision-friendly (so we can smooth it if necessary).
Budget: the base mesh is approximately 5,000–15,000 quads. No need for a high-polygon heavy asset — this is for the web.

5. Handle (rigid area)

A real die-cut hole in the geometry (the edges of the hole are real edges), at the top edge of the panel, positioned as shown in the drawing.
The handle never scales. Always the same real size and the same offset from the top edge of the bag, regardless of the bag's size. When changing the width/height of the bag, the wall changes, while the handle remains unchanged (see separation in §4).
The front and back holes are mirrored and aligned.
Two contours: straight stadium / curved stadium (see §3.4).

6. Materials (separate slots)

Assign three separate materials so that we can manage them independently in the code:

Bag film (background color — set programmatically).
Handle area / edge (can be a different color).
Print surface (for the client's layout, see §7).

No need to draw textures — only correctly assigned material slots and UV mapping are needed.

7. UV Mapping (critical for mockup)

Two independent print areas: FRONT and BACK (the front and back of the bag are printed with different layouts).
The UV of each area is flat, without distortions and stretching, 1:1 across the panel plane. The user will scale/move their image within the area, so the mapping must be predictable.
UV only for the print panels FRONT/BACK. Do not extend the print to the handle area, to the reinforcing hem of the neck, and to the gusset (in the drawing this is "gray = technical no-print zone").

8. Orientation, scale, origin point

Real proportions, 1 unit = 1 mm, base size 300×400, gusset 50.
Y-up, the front side (FRONT) faces +Z.
Origin (reference point) — at the center of the base of the bag.
Apply transformations (scale/rotation reset, applied).

9. Submission Format

Main: glTF 2.0 (.glb) — with all shape keys (morphs) and assigned materials.
Source: .blend (or equivalent) — with saved shape keys, clean mesh, UV and materials.
Additionally, .fbx is acceptable as a backup.

10. What NOT to do (common mistakes)

Do not bake folds/wrinkles into the mesh.
Do not create a finished "beautiful" render instead of a clean model.
Do not model the product inside the bag — the bag should be shown filled by shape, but empty.
Do not add details that are not in the task (seams-patterns, extra elements).
Do not create a second model for a flat bottom or for a second handle shape — these are parameters (§3).
Do not allow the handle to scale with the bag (§5).

11. Acceptance Criteria

The gusset morphs from 0 (flat) to opened — the bag stands.
The volume morphs from flat to moderately filled, the shape does not distort.
Both handle shapes are available (via morph or two variants).
With uneven scaling (narrower/taller), the mesh does not give creases within a reasonable range, and the handle maintains its size and offset from the edge.
FRONT and BACK have separate flat UVs; a test print lays down without distortions and without overlapping onto the handle/hem/gusset.
Three material slots are assigned and can be switched by color.
.glb opens and contains morphs and materials.

12. References (attach to the order)

Attach the following images to the order:

Drawing-unfolding of the banana 300×900 (FRONT / BOTTOM GUSSET / BACK, die-cut stadium handle) — main structural reference.
Flat unfolding with print (green/black, front/back different) — example of printed sides and handle position.
Photo of a real bag with a die-cut handle — for understanding the assembled shape, volume, and reinforcing hem of the neck.

Update #1 from 18 June

Task: 3D model of a "banana" bag with a die-cut handle

Type of work: polygonal modeling (Blender / subD) + UV + shape keys. This is NOT CAD (not Fusion/SolidWorks) and not a "parametric" model — a regular polygonal model with several morphs (shape keys) is needed. Size adjustments are made on our side in the code, it should NOT be embedded in the model.

Purpose

The model will be used in a web viewer (Three.js / glTF) for an interactive mockup: a print layout is stretched over the bag, and the user rotates it in the browser. A clean geometry with morphs and clean UV is required, not a ready-made beautiful render.

Product

Polyethylene "banana" bag with a die-cut handle. Reference size for construction: width 300 mm × height of the panel 400 mm × gusset 50 mm.

Construction:

Two panels FRONT (front) and BACK (back), welded on the sides.
Top is open (the neck is slightly ajar) — NOT sealed at the top.
Bottom — gusset: a bottom fold that opens into a flat rectangular base on which the bag stands.
Handle — a die-cut hole in the shape of a stadium (rounded rectangle) at the top edge, in the panel itself. The front and back holes are aligned. The shape of the handle is one — a straight stadium.
Basic shape — moderately filled bag (sides are softly convex), empty inside.

What should change — through shape keys (morphs)

Gusset: "closed → open bottom". In position 0 — flat bottom (the bag is folded), at maximum — opened base, the bag stands.
Volume: "flat → moderately filled". The volume is moderate, not "balloon-like".

(Width/height dimensions are NOT morphs; we change them by scaling in the code.)

Topology / mesh

Only quads, no n-gons (triangles are only allowed at the handle's roundings).
Smooth, even, subD-friendly mesh across the panels.
No baked folds / wrinkles / draping — the surface is calm. A slight softness of the shape is defined by volume, not sculpted in the mesh.
Handle area is topologically separated — a separate closed edge loop around the hole (needed so that when we scale, the handle remains the same size). The transition to the wall is clean, without stretched polygons.
Budget: ~5,000–15,000 quads (this is for web, a heavy mesh is not needed).

Handle

Real die-cut hole in the geometry (edges are real edges).
Fixed size and fixed offset from the top edge.
One shape — straight stadium.

Materials (3 separate slots)

Bag film — color is set programmatically (including colored material: black bag, etc.). This is a separate material, NOT a texture.
Handle area / edge.
Print surface — for the user's layout/logo (see UV).

No need to draw textures — only correctly assigned slots and UV.

UV layout (important)

The bag is printed flat, in unfolded form (on a roll), there is no seam as a structural element. Therefore:

Single flat UV layout of the entire bag, repeating the geometry of the print layout: FRONT + GUSSET + BACK as one continuous flat layout (as the print file lies on the sheet/roll). One UV island for the entire print surface.
No cuts into "two separate islands" and no wrapping around — printing is through a flat canvas.
UV is flat, without distortion, 1:1 to the geometry of the layout. Then the user's print file lays on the bag one-to-one.
The narrow side of the bag = the step of the rapport (joint with the next print cycle) — this is the edge of the UV island, not on the visible surface.
The handle and the neck fold are not included in the print UV (on the drawing "gray = technical no-print zone").

Orientation and scale

1 unit = 1 mm. Reference size 300×400, gusset 50.
Y-up, FRONT faces +Z. Origin — at the center of the base of the bag.
Transformations applied (scale/rotation reset).

Submission format

glTF 2.0 (.glb) — with shape keys and assigned materials.
Source .blend — with saved shape keys, UV, materials.

What NOT to do

Do not bake folds into the mesh.
Do not make a ready render instead of a clean model.
Do not model the product inside the bag.
Do not create a CAD model and do not embed size adjustments.
Do not cut the print UV into separate unconnected pieces.

Acceptance criteria

Gusset morphs from 0 (flat bottom) to opened — the bag stands.
Volume morphs from flat to moderately filled, without artifacts.
Handle — clean die-cut stadium, separated in topology.
Single flat UV of the entire bag; test solid fill lays without gray gaps on the gusset and sides; test logo lays in the right place without distortions.
3 material slots assigned; film color switches.
.glb opens, contains morphs and materials.

References (attached)

Drawing-layout of the banana 300×900 (FRONT / BOTTOM GUSSET / BACK, stadium handle).
Layout with printing (front/back different) — handle position, print sides.
Photo of a real bag with a die-cut handle — assembled shape and volume.

Update #2 from 18 June

Task: 3D model of a "banana" bag with a die-cut handle

Purpose

Product

A polyethylene "banana" bag with a die-cut handle. Reference size for construction: width 300 mm × height of the panel 400 mm × gusset 50 mm.

Construction:

Two panels FRONT (front) and BACK (back), welded on the sides.
Top is open (the neck is slightly ajar) — NOT sealed at the top.
Bottom — gusset: a bottom fold that opens into a flat rectangular base on which the bag stands.
Handle — a die-cut hole in the shape of a stadium (rounded rectangle) at the top edge, in the panel itself. The front and back holes are aligned. The shape of the handle is one — a straight stadium.
Basic shape — moderately filled bag (sides are softly convex), empty inside.

What should change — through shape keys (morphs)

Gusset: "closed → open bottom". In position 0 — flat bottom (the bag is folded), at maximum — opened base, the bag stands.
Volume: "flat → moderately filled". The volume is moderate, not "balloon-like".

(Width/height dimensions are NOT morphs, we change them by scaling in the code.)

Topology / mesh

Only quads, no n-gons (triangles are only allowed at the handle's roundings).
Flat, even, subD-friendly mesh across the panels.
No baked folds / wrinkles / drapery — the surface is calm. A slight softness of the shape is defined by volume, not sculpted in the mesh.
Handle area is topologically separated — a separate closed edge loop around the hole (needed so that when we scale, the handle remains the same size). The transition to the wall is clean, without elongated polygons.
Budget: ~5,000–15,000 quads (this is for web, a heavy mesh is not needed).

Handle

A real die-cut hole in the geometry (edges are real edges).
Fixed size and fixed offset from the top edge.
One shape — straight stadium.

Materials (3 separate slots)

Bag film — color is set programmatically (including colored material: black bag, etc.). This is a separate material, NOT a texture.
Handle area / edge.
Print surface — for the user's layout/logo (see UV).

No need to draw textures — only correctly assigned slots and UV.

UV mapping (important)

The bag is printed flat, in unfolded form (on a roll), there is no seam as a structural element. Therefore:

Single flat UV mapping of the entire bag, repeating the geometry of the print layout: FRONT + GUSSET + BACK as one continuous flat layout (as the print file lies on a sheet/roll). One UV island for the entire print surface.
No cuts "into two separate islands" and no wrapping around — printing is continuous across the flat canvas.
UV is flat, without distortion, 1:1 to the geometry of the layout. Then the user's print file lays on the bag exactly.
The narrow side of the bag = the step of the rapport (joint with the next print cycle) — this is the edge of the UV island, not on the visible surface.
The handle and the neck fold do not enter the print UV (on the drawing "gray = technical no-print zone").

Orientation and scale

1 unit = 1 mm. Reference size 300×400, gusset 50.
Y-up, FRONT faces +Z. Origin — at the center of the base of the bag.
Transformations applied (scale/rotation reset).

Submission format

glTF 2.0 (.glb) — with shape keys and assigned materials.
Source .blend — with saved shape keys, UV, materials.

What NOT to do

Do not bake folds into the mesh.
Do not make a ready render instead of a clean model.
Do not model the product inside the bag.
Do not create a CAD model and do not include size adjustments.
Do not cut the print UV into separate unconnected pieces.

Acceptance criteria

The gusset morphs from 0 (flat bottom) to opened — the bag stands.
The volume morphs from flat to moderately filled, without artifacts.
The handle — clean die-cut stadium, separated in topology.
Single flat UV of the entire bag; test solid fill lays without gray gaps on the gusset and sides; test logo lays in the right place without distortions.
3 material slots assigned; film color switches.
.glb opens, contains morphs and materials.

References (attached)

Drawing-unfolding of the banana 300×900 (FRONT / BOTTOM GUSSET / BACK, stadium handle).
Unfolding with printing (front/back different) — handle position, printing sides.
Photo of a real bag with a die-cut handle — assembled shape and volume.

Proposals 4 Discussions 3

Stanislav O.

131 0

Budget: 100 USD Deadline: 2 days

The task is generally clear, but there are a few points that need to be discussed. I offer my services.

Aleksandr F.

0 0

Projects -
Rating -
Rating 99

Budget: 100 USD Deadline: 1 day

Hello, I have extensive experience working with glb and gltf, with over a hundred tasks completed using these formats.

Stanislav O. 18 June

щось у вас тут всього взаємовиключного та ускладненого намішано, капець 🤔
1. наскільки мені відомо, "рівномірна сітка" в параметричних (CAD) програмах неможлива, як і деформація без артефактів. це можливо лише в програмах для полігонального моделювання. тобто, можна обрати або параметричність (регульовані розміри наприклад), або subD, рівномірна сітка і деформації.
2. у якому вигляді потрібна модель пакету - просто прямокутник без жодних деформацій (як у пдф)?