How to create This kind of Bump material

[Eelco_van_Houwelinge (Eelco van Houwelingen)]

Hi…, Does someone know if its possible with blender to create this kind of bump material on a sphere object. from the top even size holes/bumps in a round circles going downwards. (I found a picture of a Barbecue that show what i mean)

I tried it with a vonoroi texture, it doesnt give this result, its either deformd or the holes are not forming circles

[etn249]

Welcome!

I don’t think there is a way to automate it, at least not in texture form. The real life bumps on this object were likely placed by hand.

It would require a texture with very complicated characteristics:

• As dense as possible,
• Non overlapping,
• Irregular, as it needs to adapt to fit the geometry (it’s not even a perfect honeycomb pattern, some rings are misaligned and have to be).

And even if you pre-made an image texture with regular holes, it wouldn’t fit either, as it would fail at UV seams and also stretch on sections of the object.

[Secrop]

I once had an OSL shader that would do exactly that… But I lost it, and I don’t recall who wrote the script…

But you can use something like this, using a Cylindrical UVmap:

Note: you may want to decrease the X multiplier as your Y increases, to adjust how many bumps each row has, so that it fits the radius of your object.

[Musashidan (Danny McGrath)]

You could create a flat disc and bake arrays of floaters to a normal map. Then use modifier deformer to sphere-ise the shape.

[Eelco_van_Houwelinge (Eelco van Houwelingen)]

Thanks for the reply, I already thought it will be difficult with UV,s

Do you think this kind of bump is possible with Geometry nodes……

Thanks again for the reply

[Okidoki]

For evenly distributed points one can use the fibonacci sequence (section nature)

Fibonacci sequence

…sometimes called golden spiral; on a sphere also called fibonacci sphere

You may also have a look here:

100 point on a sphere

I just spent the last 30 minutes making one myself (saw your last post when I was basically finished) :). So if you want something procedural, here you go (only works in 3.0 alpha, because it needs the convex hull node): [image] fibonacci_spiral_sphere.blend (123.7 KB)

[Eelco_van_Houwelinge (Eelco van Houwelingen)]

Thanks, will try it

[DNorman]

It is fiddly to do it with uv, but if you unwrap the rows of an icosphere with follow active quads (first reset so each face occupies the whole UV space, the folow active quads)
Each row needs to be scaled a bit more than the last on the x axis to maintain the circles, and each other row offset-ed so the bumps are centered on the last. (I am sure there is a mathematical way of calculating how much you scale but I just eye-balled it.)

You have to try and get a diagonal here

[Eelco_van_Houwelinge (Eelco van Houwelingen)]

Nice didn’t think of this definitely gonna try this (when I’m back from my holiday )