Aircraft Aluminum Iray Shader

3ddd_a661099455

How about a shader for creating aircraft aluminum, complete with rivets and seams?.. It would be really cool if there was a way to adjust the seams and rivets. Also: Note the way old aircraft skin stretch and puckers slightly. Reproducing these effects with an Iray shader would be extremely useful.

richardandtracy

Not sure it could be done as a texture based shader, might have to be done procedurally to get the sort of precision you've asked for. The reason for this is the way rivets work when attaching sheets of aluminium together. The rivets will need to be at a spacing of no more than 30x the thinnest of the two joined material thicknesses on the compression side of a structure, and no more than 60x the thinnest material thickness on the tension side. The skin thickness will usually range from 16 gauge (0.16cm) at heavily loaded points to 26 gauge (0.04572 cm) in less loaded areas, with a corresponding change in rivet spacing.

Intermediate stringers and frames and their rivets need to be spaced at realistic distances too. Depending on sheet thickness, geometry and loading, a 16 gauge sheet may have a rivet line spacing of 20"/50cm on curved panels and 12"/30cm on flat panels. Down to 26 gauge and the curved panel spacing could be 8"/20cm and 4"/10cm for flat panels. The rivet line spacing in the perpendicular direction is often 20-24"/50-60cm in aircraft.

The starved cow dimples do occur between stringers and frames, and it should be noted that these are not the only shapes you can get. In some designs you can get shear web buckles. Imagine a rectangular plate, then shear the left edge of the plate downwards. In really thin sheet you can get a diagonal buckle from top right to bottom left corners of the plate. The buckle changes to bottom right to top left when the load direction reverses. This is a hugely efficient shear panel design with regard to weight, but is noisy as the buckles bang and pop as they reverse, and non technical passengers can be scared out of their wits if they see the buckles reversing.

So, just a few things to consider when making a shader as realistic as possible.

Regards,

Richard.