# how would you model this race hump

I've done a bit of modeling in blender and generally can get by, however, i'm looking for someone to point me in the right direction.

it's the hump that sits behind a motorcycle racers head, and the curves are spherical in all three axis.

everything I've tried im sure Is the wrong way about it and someone out there has a better method.

what I've tried: moving groups of points from a cube unit its close, then subdividing and remeshing to smooth it out. (bad idea).

then making it using proportional editing but having figured out how to do that via a solid object and not planes, (not manifold or similar to scan so far)

the finish piece needs to be manifold at conform pretty close to the scan.

see scan:

• why not start with a solid that is closer to the final shape, like a cone? cut it in half, etc Commented Jan 9, 2023 at 16:39
• Retopo the model you have into a model you can subdivide for a cleaner mesh Commented Jan 9, 2023 at 17:29

Learn about how the distance between edges controls the interpolation between smoothed surfaces and how similar surfaces can be created by setting the bevel weight of edges or by using the bevel modifier in combination with the subdivision surface modifier. For example, in the image below the green geometry is the same as the grey geometry. The green geometry just has a subdivision surface modifier added to it. It is also a shape that is manifold and is very similar to what you want to model. It just requires possibly some more edges to pinch some surfaces more and some points need to be better positioned to match the exact shape you want.

• wow, yeah thats perfect. thanks. Commented Jan 9, 2023 at 18:16

This might be a place for modelling with a Surface > Nurbs Surface.

With settings something like this:

.. for a fairly low resolution, reaching the corners of the control-cages.

Modelling the outer surface to your reference scan, duplicating it, and reshaping to the inner surface:

Keeping inner and outer surfaces duplicates ensures that after backing up and converting to mesh, perimeters will match, and you can use Bridge Edge Loops to create the rim between them, adjusting 'Profile' and 'Smoothness'.

You can then mark all sharp edges with a bevel-weight of 0.5, give them a Bevel modifier by weight,and a Subdivision Surface modifier. Then you can tweak sharpnesses up or down, and maybe use a little proportional editing to refine the overall shape.

• Kudos for using NURBS for something actually productive Commented Jan 9, 2023 at 22:36
• @DuarteFarrajotaRamos .. got to shoehorn them in, somewhere ... ... Oh! ... Wait a minute! ... We could make a shoehorn ! :D Commented Jan 10, 2023 at 8:19
• Now there's a cause I'd love to support. Bring back NURBS and shoehorn them into any possible answer at the expense of practicality and final quality :D Commented Jan 10, 2023 at 9:19