Blender - Simulated Geometry

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Blender: Simulated Geometry

Modelling, simulation and rendering in Blender

Introduction

– What did we set out to explore and why?

Some geometries are too complicated to create in CAD-softwares using parametric modelling. One of such geometries is cloth that often will have wrinkles, adapt to the object beneath it and applied physics.

In this project we want to explore the CAD-software Blender, in which we want to model a chair, simulate cloth to cover it and render a final picture. We want to explore Blender, as we want to learn how to model within the software and it allows us to create 3D-shapes that must be simulated to look realistic. Furthermore, we want to explore the render functions in Blender, which hopefully allows us to create realistic materials, such as cloth.

Framework & Workflow

– How did we structure our work?

To get acquainted with the new software, we started out watching a beginner tutorial about the Blender software. This went through setting up the software, familiarizing ourselves with the interface and usual workflow. There is a large community around Blender that we have consulted throughout the process.

Since this is a two-student project, we have decided to both be accountable for every step of the project, whereby we both have modelled a chair and simulated cloth.

Step 1: Modelling of the chair

We have chosen to model a real chair, so we have a reference. The chosen chair is TAKT Soft Chair. TAKT offers 2D-references for the Soft Chair, which we have used as a reference when modelling the chair and enabled us to get the proportions right.

Image: The modelling of the seat

The video shows the modelling of the chair.

Step 2: Simulating the cloth

The workflow of simulating cloth in Blender is quite simple: Add a plane, subdivide it for more detail, apply physics and press play. However, when working with simulations lots of factors can go wrong while only few make it look realistic.

Image: Creating the cloth simulation

First, we added a plane and placed it where we wanted it to fall on the chair. Then we subdivided the plane into around 40-70 smaller squares, added cloth physics to the plane and indicated that the chair was a collision object. After pressing play and viewing a very bad simulation, we tweaked, re-simulated and repeated until we got a desired result.

Image: Creating the cloth simulation

The video shows the simulation of the cloth.

Step 3: Rendering the scene

Before rendering the chair and cloth we applied a wood-texture image from TAKT. If we just applied this, we would see horrible stretching and grains going in unnatural directions. We UV-unwrapped the model and applied the image texture in the shading tab and tweaked it to look realistic. Although different shapes must be unwrapped separately, the material can be applied to all afterwards. To achieve further realism, we applied a ply-wood material to the seat and backrest edges.

Image: UV-unwrapping of the seat

The video shows the UV-mapping of the chair.

Now for the scene we created an infinity backdrop and two light-sources: a hard and a soft light. The hard light makes the hard shadows that enables us to decode the shape and details, while the soft light lights the dark parts and the environment

Image: Setting the scene for the rendering

Result

– What was the result of the project?

The following renderings show the outcome of the project. The first pictures show the difference that the outcome have when applying materials.

, The following pictures show close-ups of the details.

Reflections

– What are our thoughts on the project?

Certain operations that would otherwise be complex in parametric modelling such as smooth transitions and organic shapes, such as the bending of the backrest and seat, are much simpler as we are free to move the geometry and not constrained to tools such as lofting. By far the most difficult part of modelling with the mesh was maintaining a proper topology, which is a rectangular mesh. Making the hole for the screws could be done easier by a Boolean modifier, however, this would require more cleaning up of the mesh to avoid stretching and pinching.

Simulating the geometry was very difficult to get right and required lots of tweaking of the parameters.