Two Ways to Do Two Totally Different Things

The prompt, to compare the appropriateness of Grasshopper and Digital Projects in different situations reminds me of a similar question that I asked Dennis Sheldon last year.

How would you compare the design philosophy's of Digital Projects and other parametric softwares like Grasshopper?

If I remember correctly he said that Digital Projects was designed for really detailed projects that required a level of engineering and finesse in their design that Grasshopper could not provide. It touches on the difference a little bit, but for the most part, does not stray from marketing speak.

One thing that neither software does well is loops, I think that is one of the most important distinctions that should be recognized, since it prevents them from acting really well in the context of generative design. That is not to say that they can't do repetition well, but it certainly cuts down on the amount of "cognition" that either can have about the forms they are creating.

I'll start with Grasshopper.
Its definitely not as powerful as Digital Projects, but in the same way, it actually allows you to sketch out a design in it. As long as you can manage the lists properly and get through some funky logic to get things done, it allows you to make a series of design decisions and play with the parameters that make up the resulting form. In this way, a system can be designed and repeated with varying changes to the parameters each time the initial system primitive is repeated. The transition from Rhino to Grasshopper is not that hard once you get used to programming since the commands are roughly the same. Thus is allows you to build something just like you would in Rhino, but give you the flexibility to change the design after the series of commands is complete. Thus, it is really good when you only have loose idea (or no idea) of what the final form is going to look like.

On the other hand, Digital Projects almost necessitates an understanding of how the final object is going to look. While there is an impressive amount of manipulations that can be made to objects, their basic structure stays the same. Thus, its good when you are designing a system of similar parts. Parts like custom joints that all have the same basic form and structure, but at the same time, need to be flexible to accommodate the different positions of connection points. While the larger form is relatively static (or within the positional tolerances of the joints) the software is extremely flexible when it comes to managing all of the different combinations of joints that can be made. With this ability, and the reason that Gehry likes it so much, is that the form can be warped, shifted, and bent out of shape, and the model will stay together and each part of the construction will adapt to the changed form or structure. While new form cannot be generated, it can be detailed and analyzed in various positions in a way that would be next to impossible in grasshopper.