Which software to use for occasional need of 3D modelling and rendering?

Hi,

I'm a construction engineer working with easy architectural design (45%), structural desgin (25%) and building permits for different projects (30%), for example renewal of the plumbing in 4-12 story apartment building (%= the time spent overall). I'm using basic AutoCAD in 2D, applied with domestic applications that makes the designing faster.

95% of the time I´m not in need of 3D desgin and as I'm not an architect I don't need to sell and market my designs by creating beautiful 3D pictures. But occasionally a customer would like to see their building in 3D with materials and colors. In these rare occasions I create different types of colored hatches to the 2D facades and that gives the customer a glimpse of what the building will look like, but of course it would be nicer to show a rendered 3D model. The same thing is with the bathrooms, that have to be "demolished" and renovated in apartment buildings, because of the renewal of the plumbing. In many occasions the residents would have liked to see how their bathroom would look like in 3D with different types and different colored tiling, sinks, toilet seats etc.

What software would you use in situations like this for fast 3D modelling and good quality rendering based on your dwg-files? Of course it would be really nice to get an Autodesk Building Suite license and start using Revit or AutoCAD Architecture combined with 3Ds Max but I've watched numerous tutorials and tried the trial periods and found them really time consuming to learn and this wouldn't be reasonable because I rarely need 3D modelling.

Hopefully someone has been in the same situation and come up with a great solution

Well, the best solution would be the one you already described. Get an Autodesk Building Suite license. But if you only need 3D renderings occasionally, you won't be able to justify the cost of the suite, and the learning curve on these programs is pretty steep so you will need to devote a lot of time to learning them. One option you might want to consider, since you only need 3D occasionally, is to farm your 3D work out to a freelancer. I'm always looking for new clients, so if you feel like this is a viable option, click on the link in my signature, take a look at my portfolio and contact me for a price quote.

Other options would be to use Sketchup, (The pro version costs around $500 I believe), and you would need to purchase a 3rd party renderer such as Twilight, Vray or Maxwell. Or you could use Blender, it's free. You will need a .dxf import plugin though, in order to import your CAD models.