Newbie needs help with stones

Support Materials and Textures
1

Hey guys!
I am completely new to Blender and this forum, just getting into it since monday. I need some renderings for a project in my design study and blender seemed like the right choice.
As a product Designer I usually use SolidWorks, but now its about organic shapes and materials. Completele new to this stuff I might have a bunch of questions and I hope this would be the right area in this forum. It probably fits into several areas.

My project is about the differences of natural and artificial material, in this case stone and plastic (polyester resin). I want to make a mold froma a stone and cast a duplicate in resin. The stone will be ground on two sides, so that it does not wiggle and so that it can be used as a stool or side table. Hopefully you get the idea.

Now to my blender questions:
I am quite satisfied with the plastic version of the stone, even though there is probably a lot of room for improvement.
The “real” stone looks a bit damp and unrealistic, but I tried to do it just with onboard things (like in this tutorial: https://www.youtube.com/watch?v=5v8pzsYImc8). My idea was that I can change the color/material in the node editor and would have the same texture in the plastic version. Kinda works, I think.

Now I would like to have two completely flat and shiny surfaces on both of the stones. Probably with two different materials on one object. There is pictures attached, how it could look in the real world.
The bisect tool seemed to be something useful, but the surface it creates is not really like the flat surface I imagined.

I would like to get into it a bit more before attacking you with so many (probably pretty easy to solve) problems, but my final presentation of the project is in two weeks and time is running out.
So there is a lot of problems where I might need some help… Is there anybody out there? :slight_smile:

Thanks!
David

2018-01-31 11_15_34-Blender_ [C__Users_pc_Documents_Blender_Stone_Renderingtest_rock.blend] Kopi.png1346×888 152 KB

presentation-03.jpg1754×1241 294 KB

Attachments

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2

You have cut the top and made a big n-gon, which is a face with more than 4 sides. That won’t subdivide nicely without support edge loops.

The multiresolution and subdivision surface modifiers don’t make sense. If you’ve used multiresolution for sculpting and then cut the model, the modifier remembers the sculpting done on each subdivision level and changing the geometry afterwards could make a mess.

If it’s just for subdivisions, that can be done with subdivision surface modifier. You don’t need very high subdivision level for rendering because the edges can be hidden with smooth shading. If it’s for 3D printing, the importing application only interprets geometry and you do need higher subdivisions.

Select the n-gon, outset with i+o (i for inset, o to switch to outset) a bit, then inset to get another loop on the other side. N-gon selected, mesh menu -> clean up -> split concave faces. If the face really is flat, that should be enough to support the subdivisions and have a clean looking result.