# Creating Scratches in Modeled Surfaces

#1

I’m quite a Sketchup novice and would appreciate guidance from the more experienced users here. I am attempting to model scratches on the surface of a metal object, in this case a chisel, for use as a demonstration of a sharp edge. I suspect that this can be done using either the push/pull or the follow me tools. The scratches would in real life be very shallow but still visible to the human eye. Ideally, I would like to be able to magnify or minimize them by zooming in and out, to illustrate the effects of magnification during the sharpening process.

I have downloaded from the 3D warehouse a model of a chisel, so I do not need to create that model from scratch. I just need to place small scratches (as would be left by abrasives) into the surface.

Thanks for any and all help!

#2

hi @jszens,
have you considered apply a texture to illustrate the surface condition?
it may be more effective then actually modelling fine detail…
john

#3

No, I haven’t tried that. I am after the fine detail…the whole point of this little exercise is to illustrate that an edge that looks really sharp can actually be pretty beat up if you look close enough. Thank you for the ideas…if I can’t get done what I want I will explore your solution.

#4

That’s probably the one thing at which SU is the poorest. Fine details bleed together on screen and bog down the system. The idea is really double trouble. If you want snappy transitions between magnification states, however you choose to present them, you want to minimize geometry. Modeling a bunch of microscopic grooves and fissures could be as resource greedy as modeling a patch of the moon’s surface.

You may be able to take advantage of the ability to scale textures, or, for that matter, you could use a separate image taken at each resolution applied to a series of chisel copies (pieces of chisels) in a series of scenes.

A model with an image texture painted on it can be amazingly realistic, and doing it that way would take advantage of SU’s strengths and avoid its weaknesses.

-Gully

#5

#6

Model the basic geometry of the chisel. If you then want to show the finish at 10x, 50x, etc., you can either copy and scale a piece of the model or just remodel a small chunk of it (obviously, the higher the magnification, the less it will look like a chisel–it will be just a chunk of something).

Clearly, the images you come up with showing the fine detail will make or break the demonstration, Really, except the full-scale version, the geometry of the magnified pieces will be very simple, and little more than an easel on which to position photos in 3D space, although that might be quite an effective way to present them.

So the question arises: do you have a clear set of photos that show what you want to show, which you can paint onto appropriate models or pieces of models?

-Gully

#7

No photos, since these would be micrographs in order to be accurate.

I thought I might just be able to model the scratches into the surface of the chisel.two parallel lines with a little arc at each end…anyway, this seems like it’s more difficult than I thought.

#8

it might not be difficult at all.

i’m thinking you have something in your mind of what you want to accomplish but we’re not reading what you’re imagining.

it sounds like you want to model a detailed or semi-detailed chisel which you could then zoom to the cutting edge and see micron sized gaps/nicks/etc… in which case, sketchup wouldn’t like that too much.

but if you just want to make a model of the cutting edge as it would be seen under a microscope… something like this except extruded in a third dimension:

then that’s possible to do.

do you have any sort of graphical representation of what you’re trying to do? or a clearer way to describe it?

but if you’re trying to make a sketchup model like this:

then you zoom in some:

then you zoom in a lot more:

srry, i don’t think that’s going to happen

(the pics are `chisel-> plane-> knife` but you get the idea )