making a "pitted" surface texture

[anselm Hexicola]

I was thinking of making the surface of my latest mesh-build have a ROUGH appearance even its geometry was comprised of a few flat planes.

My intention was to create a high poly version from which I could then get an Ambient Occlusion for the basis of the Diffuse texture, and maybe experiment with Normal and Specularity maps. (I think I can do that bit...)

I use Blender and Gimp.

My question to you more experienced/proficient users of 3D drawing tools is this:-

  How might I go about  "deforming" a flat plane to get the high-poly version? I don't want to spend ages creating by hand obviously; is there a Brush or something like that in Blender that will generate such a topology ( think sand-paper, only inverted if that makes sense)?

  (I know I am being a bit lazy asking for tips rather than trawling through the Blender manual and/or online tutorials.)

[Chic Aeon]

i think your best bet would be to generate the normal from a rough TEXTURE. This works very well and is quick and easy (also tilable in most cases). Since lots and lots of folks don't see normal maps, be sure not to rely ONLY on them. Good texturing which can simulate a rough surface would be a first step.

 

I use ShaderMap 2 and I am very happy with it. There are other programs out there and I suspect some GIMP folks may be able to give you more info.

 

Good luck!

[Scooter Hollow]

Using a normal or a displacement texture, you can create a bumpy mesh in Blender. Some recommended steps:

 

1. Start with a regular diffuse texture, with your pits colored in in whatever form.

2. There's a Gimp plugin that will get you normal maps from an image, you can probably google it.

3. To make a displaced mesh, you can use a normal map, but normal maps often have a lot of small details you don't want in a displaced mesh because it would explode the size hugely. Note that you don't neccesarily want a displaced mesh at all, I've been playing with it recently in OpenSim* to neat effect but I haven't seen anyone else doing it, and a Normal map may be enough in a lot of cases.

You probably want to make a displacement map from scratch, a simplified form of your diffuse with black and grey where you want the pits to be.

4. In Blender, take a flat plane mesh, go to edit mode, unwrap it, subdivide it a few times (my computer here can generally work with up to 16k verts, maybe the 66k subdivide before it gets crashy). Go back to object mode, add a new material, add a new texture, set it to image type, and input your displacement map.

5. Add a Displace modifer. You'll probably want to drop the strength down quite a bit. If you need it more tiled or offset, you can adjust it from the texture mapping settings. When good, apply the Displacement.

6. You'll probably have a lot of leftover verts you don't need anymore. Add a Decimate modifer, select Planar, and the default 5 degrees should probably clean it up enough.

Viola, a displaced mesh that you can then upload and then apply your normal map to for even more detail.

 

 

Here's a one example of what I've been playing with. The bricks are a displaced mesh, with a normal map on them for the smaller details. The door is also a displaced mesh (could've been done with prims, but I was trying things out).

 

 

*Side note, I started playing with this since we're working for some OpenSim users who are tied to a viewer that doesn't have materials yet, and I wanted to see if there was something else I could do.

[anselm Hexicola]

Thanks Chic for your post.

For sure, I wont be relying on the Normal map for the mesh's appearance; my PC is not high spec and my internet is poor(I live out in the sticks) so I don't have Advanced Lighting enabled myself ! If I am very still and careful, I can put it on long enough to do a screen capture - which is all I want. I want to use the AO bake to make the Diffuse texture - the rest would be the "icing on the cake".

But really what I wanted to know was there a way to make this kind of dimpled/"pitted" mesh with a tool in Blender.

[anselm Hexicola]

Scooter, I am still absorbing the info you kindly put up (so maybe the following misses the point...)

I am wanting to work from mesh to texture; I want to generate a high poly mesh from a flat plane in Blender and then go from there...

Quite possibly there is no simple way to do this, but I was wanting to know if there was a tool/technique in Blender to generate a grainy surface.

[Drongle McMahon]

1. Add plane. plane
2. Subdivide 3 times (or once with 7 cuts).
4. UV map.
5. New material.
6. New texture - leave as clouds,
   a. Set Mapping:Coordinate to UV.
   b. Set clouds:basissize to 0.05
   c. Uncheck Influence:diffuse:color
   d. Check Influence:geometry:displacement
   e. Set Influence:geometry:displacement to 0.05
7. In UV editor, Image:new:256x256 blank
8. Camera:bake ...
   a. Make sure Selective to active is unchecked.
   b. Check Normalised.
   c. Set Bake Mode to Ambient occlusion
   d. Bake
9. Image:save ... this is your ao map.
10. In object mode, make a new plane and put it eacatly aligned just underneath the first one. Don't subdivide it. (you can align them bu doing transform>origin to geometry on each and then setting their X and Y positions identical).
11. Select the new plane, then shift-select the old one.
12. Camera:bake ...
   a. Set Bake Mode to Normals
   b. Set Normal Space to Tangent
   c. Check Selected to Active.
   d. Bake
13. Image:save ... this is your normal map
14. Upload to SL and apply aomap as diffuse, normal map as bumpiness, set specular map to blank.

You can Set the duffuse colour for variation, or you can combine the ao map with another texture by using multiply mode in GIMP or PS.

There are infinite variations of the above with different textures and different and additional parameters. Experiment in Blender by rendering with a couple of lights. Then there are specular maps...

 

This was for a 256x256 texture with one vertex per pixel fot the
displacement. You can get better results using more subdivision.

Here are the maps made as above, a Blender render, and what they look like in SL, 2x2 on a prim cube, rusty tint, blank specular map with default settings. With higher repeats there is a just discernable seam. If you need to remove that, you have to make the maps seamless, which is a different story.

[Drongle McMahon]

That was using geometry, which is what you asked for. However, there is a much easier way. Here are the equivalent pictures using a different generated texture from Blender (Musgrave Hetero Terrain with tweaked parameters). This time I just used a simple plane with no subdivision, UV mapped, set the texture to Influence only the normal, and baked the tangent-space normals onto itself - no second plane required. This gave the normal map. Now, instaed of a AO bake, I used the method I described in this thread to make a cavity map from the normal map in GIMP. Used the cavity map as the diffuse texture with a rusty tint, and the normal map in bumpiness. Blank specular map with a bit of glossiness added (25).

The again, depending on what you are looking for, you might want to use diffuse and normal maps that are based on completely different textures. That can provide a different sort od effect.

[anselm Hexicola]

Well, I got to experimenting this evening, trying hard to take onboard the often detailed explanations from Chic,Scooter and Drongle.

@Drongle - I got frustrated trying (and failing) to make the cloud AO Diffuse map in Blender, even though I thought I was following your step-by-step guide - dont know where I was going wrong. Anyway, in the end I made one in Gimp by a similar method (white x256 layer - Filters - Render - Clouds - etc.)   I used this as my Diffuse texture and managed to derive a Normal map texture from it in Blender.

I was pleased with the result when I did a Local texture "paint" on a selection of prim types inworld.

   ...especially the half-decent tiling round the corners. 

HOWEVER, the good visual effect is ruined when the camera pans out to show the top and (here hidden) bottom faces of the prims.

 

On those faces the normal map is not contributing its 3D effect. I don't know why (obviously since I am a novice in this). Any of you able to explain?

 

PS. Drongle, I will try your alternative method (as outlined in your 2nd post) this weekend. And, thanks for your precise and informed contributions in this and many other threads - good reading!

[Drongle McMahon]

If you have specular (glossiness) but no or low environmental reflection, then whether you can see the effect of the normal map depend on the angle of the sun and the or the camera. You can see the effect quite well with the diffuse lighting where the light is glancing the surface, as on the sides of a cube at midday, but on top, te diffuse reflection is much more even, so that you mainly see only specular effects, and these are very angle dependent. Here, for example, is the set of cubes from that other thread, viewed with the sun set at 3pm, either looking towards the sun (top) of away from it (bottom). The top looks much flatter in the sencond view because there is no speculat reflection from that vcamera angle. There is only a bit of lighting variation from the normals because the sun is still pretty much shining down on the surface. I think this is the sort of effect you are noticing. This is one of the reasons for using the cavity map, as on the middle cube.

[Chic Aeon]

Just wanted to say I LIKE THE EASY ONE BETTER   !!!!

[Chic Aeon]

That was an excellent photo that shows the "issues" well.

 

I added materials to the last builds I made in SL. I have and will likely add them again on another grid .

BUT that being said, I am not really in the "materials" camp mostly because it IS so dependent on the Windlight (sun angle) setting. Oftentime one side of a building looks as you would like it and the neighboring one  -- that you can ALSO see -- looks completely flat. 

Really doesn't work that well for me -- either normal or specular for the same reasons. AND there is that extra download.

What I HAVE find that I like and have used is taking one of the maps from ShaderMap and adding that as an overlay (forgot now exactly what merging I used) on the diffuse texture. That gives a great look with no extra download an no dependence on the Windlight setting.

A few futuristic thinkers in SL were using this method many years ago and their work REALLY stood out. I of course had no clue what they were doing then, just that it looked really good - LOL

 

 

[anselm Hexicola]

Well, as promised/warned, I continued to experiment with making this; this time also trying out the Cavity map thing.

( all textures/maps are x256 )

First I made the base texture in Gimp.  Default white background layer, then Filters - RGB Noise ( uncheck Independent RGB, sliders down to 0.1 );  Filters again - Gaussian Blur ( radius right down to 1.0).

Next I produced the Normal map in Blender.

Finally I used Drongle's method (as referred to in his link ) to produce a Cavity map.

          

 

( Drongle's method of showing varying permutations in the 1 screenshot is very helpful, so I have shamelessly done the same in my own inworld screen captures.)

These are 3 versions of the same simple mesh (supposedly a stone finial ..)

Sun is midday; all coloured beige.

All 3 have Specularity ( Blank with no Glossiness and Environment set at 20; colour=Black)

All 3 have the same Normal map (middle above).

As for the Diffuse texture, the nearest one to the camera has the base texture (left above); the middle one has the Cavity map (right above) and the far one has the SL Blank texture.

(Texture Repeats for Normals and Diffuse were 10, I think -forget now, something like that.)

 

      Advanced Lighting ON

 

 

     Advanced Lighting OFF

 

I wanted to have the best of both worlds, as it were, namely texturing an object that looks OK-ish whether Advanced Lighting is enabled or not. 

 My own conclusions:-

   1. To my eye, there is no appreciable difference between the 3 with AL on.

   2. With AL off, the Cavity map works fairly well on the middle one ; the base texture is barely discernible in the near one.

   3. It was a bit of a juggle getting the base texture right so that the Normal map didn't get generated too strongly. I feel the effect is too strong/harsh in my "AL On" picture. 

[LepreKhaun]

Wow, it's amazing what I find myself learning while watching over the shoulder of a good student. Excellent thread!