when talking about 3D modeling software there seems to be a difference between Blender and CAD Software, are they different? Is Blender CAD Software?
No, Blender is not a CAD software. CAD software relies primarily on curve modeling while Blender primarily relies on polygon modeling. CAD Models are a collection of shapes defined with math while models made in Blender are collections of points connected by edges and face.
In the rest of this article, we'll go into more detail about CAD software and how it differs from Blender. We'll also cover what you can do to still use Blender as a CAD software and cover some relevant questions.
By default, Blender isn't CAD Software, the main reasons for this are the Blender simply isn't made with the idea in mind to create 3D models for construction and engineering. It is built to create 3D art and animation. There is a clear distinction between these two kinds of software.
If you want to create art, use a tool for that. If you want to engineer, use a tool for that. Blender is primarily on the art side, but both kinds of software certainly have some overlap.
Blender uses polygons and vertices to define the shape of an object while CAD is mostly non-destructive and uses math to define shapes. CAD software also emphasize using exact values when defining shapes.
CAD software also provides many tools for engineering, whether that be for designing blueprints and architecture for buildings or designing a circuit board.
While Blender doesn't have very many tools for CAD out of the box there are a few addons that extend Blenders CAD abilities.
One of the main addons currently being developed to extend Blenders CAD abilities is the Blender BIM Addon. The website also contain links to a few other popular Blender CAD addons such as Sverchok.
External Content: Blender BIM Addon
There is also CAD Sketcher, a newer addition to the army of Blender add-ons available for free.
External content: CAD Sketcher Gumproad page
One major difference between CAD and Blender as well as other 3D modeling applications is that most workflows in Blender require destructive modeling.
Destructive basically means that to model something we need to make permanent changes to the object.
For example, if we move the faces and vertices of a model we cannot disable and enable these changes. They become part of the model once we make them. Of course, there are exceptions to this, and the exceptions grow for every release of Blender.
One prime example is the modifier stack and the recent addition of Geometry nodes that completely change this for Blender.
Related content: How modifiers work in Blender, an overview
Related content: How to scatter objects with geometry nodes in Blender
Typically, in a CAD software we can undo and redo any changes. But in Blender we cannot pick and choose which changes to undo or redo to the same extent.
Related content: Blender 3D: undo, redo and history
CAD models contain a list of each function that creates the model. We can go back through each of these functions and the settings. We can add a hole into a model and make many more changes on top of that and later still go back and adjust the size and location of the hole.
Blender does have modifiers which we can use to modify models without directly changing the base model, but we can only model so much using only modifiers. We sometimes also need to apply modifiers to do further manual adjustments to create the shapes we want.
Related content: How to apply modifiers in Blender
In general Blender is not similar to CAD. It does have some Non destructive tools.
It is easy to get into the idea that one is better than the other, but CAD software and 3D art and animation are simply just two different things. If you want to construct stuff, then use a CAD software. If you want to create film, VFX or 3D art, choose a 3D art and animation software.
Blender's modifier system is somewhat similar to CAD and updates that work towards making everything node based will likely create more opportunities for a none destructive workflow in Blender. Geometry nodes also add more tools to the none destructive workflow.
Blender is starting to get more tools for a None Destructive workflow but accuracy is still an issue and even if we could create CAD models in Blender it is still missing many of the tools that streamline the CAD modeling process.
The difficulty of each program is relative to what skills you're comfortable with. Each program requires you to get comfortable with the concept of working in a 3D space.
For CAD you mainly need to be competent with measurement and the math used for architecture. If you know how to use math to define shapes then CAD likely won't be too daunting.
In Blender most models are an abstraction of what we're trying to create. While we can use math and measured values there's is usually a lot of changing models by hand. We mainly need to rely on our eyes to get the shape of a model right. This is somewhat of a skill and takes a while to develop.
While Blender doesn't contain many of the features used for creating architectural models it is much more suited for architectural rendering.
Most CAD software don't include any advanced rendering system. This is where Blender can come in handy in the CAD workflow.
Related content: How to render in Blender
We can bring the model into Blender and then add details such as materials and setup lighting and a scene. We can also add assets to the scene that aren't CAD models such as trees for an architectural render of a building or decoration for a home.
Outside of Architectural Rendering and possibly some hobby projects though Blender isn't used for any actual engineering.
A few of the most widely used CAD programs are AutoCAD, Solidworks, FreeCAD, and Sketchup.
The best CAD software to use depends on what you're trying to achieve. AutoCAD has features that are much better for architecture and design blueprints and in general working in a 2D workspace.
Solidworks is great for complex 3D objects, it has a model tree that allows for easy adjustment of each feature of a model.
There are many other CAD software and the right one to choose depends on what you want to use it for as well as your budget.
While Blender doesn't support the unlimited detail that CAD supports we can still use it for 3D printing.
The usual workflow for this is to setup the model in Blender, and then export it into a 3D printing software that will format the model to be printable. This will include setting up scaffolding so the model actually prints as well as cutting the model into layers.
One important detail to keep in mind is that you can't do smooth shading with 3D printing, your model needs to be dense enough that the resolution of the mesh is higher than the resolution of the 3D print, otherwise you will have visible polygons on the 3D printed object.
The models for this usually also need to be manifold and not include any clipping. Models that have clipping can cause many issues when formatting them for printing.
While Blender is great for 3D modeling its CAD toolset is very much lacking and in general Blender doesn't have certain tools that are key to CAD software.
Blenders models are polygon based. Their resolution can only be as high as what we've modeled. Since we define CAD models mathematically, we can export them at any resolution we need.
In general Blender works well in an artistic and quick none-precise modeling workflow. CAD is good for precision and accurate non-destructive modeling.
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