Earlier this month, Phi announced its new subscription plans: Essentials, Professional & Enterprise. 

Whether you're a freelance designer or part of a larger design organization, these plans are tailored to cater to your specific requirements and make Phi even more accessible to the wider 3D design community.  

To celebrate this, we wanted to republish this article with some updates.



A quick Google search for “product design” reveals what we already see around us: Most design involves freeform organic surfaces.

Yet, freeform design has been notoriously hard. Current solutions employ different approaches, each with pros and cons, with the cons often outweighing the pros. 

Phi is a new type of surface modeler for Onshape users, that allows quick and easy interactive modeling of surfaces without sacrificing precision and quality. It's available as an integrated cloud app in the Onshape App Store.

Phi’s “slick surfacing” places the technology in great company with giants like HP, Intel, and innovative tech startups like Lumafield (also an Onshape user).

Phi has also received illustrious recognition by DEVELOP3D for being one of the top 30 technologies in 2022! 

The D3D 30, a yearly list from Develop3D, is an exclusive list of technologies that “have an important role to play” in product development, chosen on merit only. 

How Does Phi Work?

Based on n-sided patches technology, Phi is a curve-based modeler that allows unrestrained editable curves – so you can focus on your design intent while it automatically generates watertight, high-quality surfaces. This integrated cloud app is accessible within an Onshape Document tab and can push and pull these complex designs to and from Onshape. 

Phi’s unique curve-based approach is quite different from existing design processes. The curves allow a great deal of freedom to achieve interesting shapes interactively with just a drag of the mouse!

Watch the Onshape webinar, "Add Freeform Surfaces to Your Designs with Phi," to learn more about designing with Phi.

Phi Subscription Plans

Let’s take a closer look at what each Phi subscription plan offers:

Essentials: Perfect for individuals who are starting with freeform designs, the Essentials plan provides core features to enjoy a streamlined experience without compromising on essential freeform functionalities. Essentials is only available on an annual plan. 

Professional: Designed for Professional Designers and Design Teams, the Professional plan offers advanced features and additional capabilities. Unlock the full potential of our product with these comprehensive subscriptions. Professional is available on either a monthly or a (discounted) annual plan. A 30-day trial is available for this version. 

Enterprise: Phi also offers custom solutions for larger designer teams and advanced workflows. To learn more about the Enterprise solutions, contact Phi.

Convenient Subscription Management Directly from Phi 

While you can still access and use Phi through Onshape, subscription plans are now available to purchase only directly from the Phi website. Now, you can complete your subscription directly through Phi’s website with the secure and efficient payment processing offered by Stripe Payments. This ensures a hassle-free transaction experience, giving you peace of mind.

Suppose you had already subscribed to Phi for Onshape before. In that case, you will be redirected to Phi’s website to select one of the new subscription plans available before re-accessing the application. Select the subscription plan that suits you best and return to Onshape to continue enjoying access to the Phi app directly through your Onshape account.

Watch this quick video explainer about subscribing to Phi.

Phi for Education

Continuing their commitment to make advanced surface freeform modeling accessible to academia, the Phi surface modeler is free for educators who use it as part of their curriculum in their classes. 

Students can also get a Phi for Education subscription for free for one year. Any other student or educator can apply for a discount of 85% for the Professional version. You can fill out this form, and the Phi team will process your application within 5 working days. 

Start by experimenting with your own design ideas or following our guided examples or tutorials provided within the application. 

Surface Modeling with Phi

To give the product designer more control, Phi has incorporated tools such as:

  • Various Smoothness and Tangency Options

  • Selective Symmetry for Flexible Mirroring

  • Carving 

  • Precise Scaling and Moving, alongside the freehand option

  • Attach surfaces to scanned STL data


Watch a quick overview of Phi below:

The following video shows a few simple design examples and how you can tackle them with Phi:

You can find additional material on Phi’s website

Try Phi Today!

Phi is in rapid development, with many exciting features and enhancements coming soon, so keep an eye on this space!

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This blog was first published on April 26, 2021, and updated on February 20, 2024. Stephanos Androutsellis is a co-founder of Phenometry, the developer of Phi.