Create a wooden floor from a set of textures

Question

I’m trying to create a wooden floor from a set of textures. My idea is, to use one image for each floor board. Thus, I create appropriate scaled cubes for every floor board and want to randomly apply one of my floor board textures to each of those.

This works pretty well to the point where I want to limit the generated floor to the extents of a room. At this point everything falls to pieces.

I tried two approaches. One using the Array Modifier and the other using Geometry Nodes, which is my favourite. As both are using the same material, I will first explain my material. Afterwards I will explain the approaches.

I would like to stay non-destructive. Nevertheless, I tried destructive workarounds, which led to other or similar problems.

How can I solve this?

Material

My idea is, to stack all textures of a type in one image. Thus, I can choose one of them by choosing the corresponding range of y-coordinates. As I’m still in the proof of concept, I don’t currently use wood textures. Instead, I created a structured image with different colors, where every color represents one wood image:

Here is my material:

And this is how the node “RandInt – Color-Index” works:

The Geometry Nodes Approach

I’m using the following Geometry Nodes setup:

When muting the Realize Instances node, this creates the following result, which is fine:

When I try, to limit this to the extents of a room by applying a Boolean modifier, nothing happens.

And when I unmute the Realize Instances node of my Geometry Nodes setup, the Boolean modifier works but my material does not work properly anymore:

The Array Modifier Approach

I added two Array modifiers to an instancer object like this:

This gives me the following result:

When I apply a Boolean modifier on the instancer object, it does exactly what it says: It intersects the instancer objects but not the instances. Instead, it creates one complete floor board instance for every instancer object, that remains at least partly after the boolean operation:

My blend file

Answer 1

i found one "cheap" solution via shaders like this:

Create a plane (or whatever object you like), then extend your shader nodes like this:

set blend mode to alpha blend

and you can limit your texture with the greater/less than values:

...but i don't know whether you are looking for practical "solutions" or "theoretical" perfections...because this is "just" a solution.

Answer 2

As proposed by @TheLabCat , one solution to this problem is, to set the material using geometry nodes. Instead of using the complex material from above, I added 3 simple materials to my floor board:

Then I activated the Realize Instances node in my geometry nodes and set the material index to a random value:

After doing this, the boolean modifier works properly:

But uv-mapping breaks, when I replace the simple colored material by a texture-based material with an UV-Map. Following, I will explain, how this can be fixed.

I created three materials red, green and blue, that use the following images as texture. The black and white stripes on left are intended, so that it is easier to see, if the material is aligned properly.

The following image shows how these materials look like. I will explain the Texture Mapping group node later on.

As the UV-Map breaks, when the Realize Instances geometry node is activated, I switched the texture coordinate in my material to Object and set the scale by using a Mapping node to the extent of one floor board (2.42 x 0.178).

But that still is not enough – every row of floor boards is shifted in x direction compared to the others. In order to consider this shift-value, I capture the position attribute of the faces just behind the Realize Instances geometry node and expose it to an attribute named x-shift in the Group Output.

And all adjustment of the texture happens in the Texture Mapping group node, that has been mentioned above. This is, how it looks like inside:

I will explain this, starting at the mapping node on the right. As already mentioned, I use the Object output of the Texture Coordinate node for the basic texture mapping. Therefore it is plugged into the Vector input. The length and width of one floor board are expected as an input into this group node. They are used to define the scale of the texture mapping.

To realize the x-shift of the floor board rows, I grab the value of the x-shift attribute of the Group Output from my geometry nodes, by using an Attribute node. For some reason, the position attribute of the faces seems to reference the center of the faces. Thus, I have to shift the shift-value by half of the floor board length, which happens in the two blue Math nodes on the left. The result is written into the x-coordinate of 0-vector, which is used as the location of the texture mapping.

And this is, how it looks like: