Introduction

Welcome to our product!

This is a package containing procedurally generated models of some of the fundamental arches used in architecture. A round arch, a pointed arch, a segmental arch, a three-centred arch and a horseshoe arch. 

What do you get

In the .blend file you will find models of the five arches mentioned plus a model of a doric column, as an example, if you want to try replacing the default column of the procedural model, as described later.

All models come with UV maps and with pre-configured materials, ensuring seamless integration into your projects without the need for extensive setup.

How use models in your project

To add the models in the asset library, unzip the .zip file downloaded from the store and copy the content in your asset library folder.

For example in my computer the library folder is located in “/Users/bianchinis67/Documents/Blender/Assets” as you can see in the picture below. Check what is your library folder path opening “Blender Preferences” window and look in the “File Path” tab. 

Once this is done the models will appear in the asset browser, ready to be drag and drop into the scene.

Models parameters

As previously mentioned, models are procedurally generated using a set of geometry nodes. This approach grants you the flexibility to tailor the appearance and structure of the models by adjusting the parameters within the associated modifier.

To access these parameters:

• Select in the scene the desired model.
• Navigate to the "Property Editor" view.
• Locate and select the "Modifier Panel" (identified by the icon )

Below is a comprehensive list along with descriptions of the parameters utilised for each of the five models: 

Show arch: flag to show or hide the arch (only the upper part, columns excluded) in the rendering.

Span: is the distance between the two piers.

Rise: it is the maximum vertical distance between the top of the intrados and the impost line of the arch. This parameter is not present in the round arch and in the pointed arch.

Springing level: height of impost line: i.e. the horizontal straight line that passes where the arch begins and the piers end.

Depth: the distance between the intrados and extrados.

Vault length: the depth of the intrados.

Resolution: determines the subdivision used to draw the arc (it is recommended to keep this value low, increase it only if necessary)

Show L column e Show R column: by activating or deactivating these flags you can choose whether or not to render the left and/or right column.

Columns width e columns depth: column size. These parameters are ignored if the Columns override parameter (described below) is use

Columns override: if instead of the rectangular-based columns generated by the model you wish to use a more complex type of column, then you can specify the object to use as a replacement for the "standard" columns in this parameter. For example, if in a rounded column you select the "Doric column" object (which you find among the assets) you will obtain a result similar to the one shown below.  

Col. overr. offset H cm: has the purpose adjusting horizontally the position of the columns. Is used only when using the column indicated by the “Column override” parameter. If it is 0 (the default value) the columns are positioned so that the innermost point aligns with the intrados of the arch.

Col. overr. S level offset cm: adjust the height of the impost line relative to the top of the column. This parameter is also used only when the model indicated by the "Columns override" parameter is used as a column to adapt the geometry of the arch to the geometry of the column. If it is 0 (the default value) the impost line will be placed to align with the top of the columns.

Show wall: activate or deactivate this flag if you want to render the wall around the arch or not.

Wall width, Wall height e Wall thickness: obviously they specify the dimensions of the wall.

Additional parameters in the pointed arch

All five arch models share the parameters just described, the only exception is the pointed arch which has two additional parameters.

Centers span: the pointed arch is drawn by joining two circle arcs with centers positioned on the impost line symmetrically with respect to the midline of the arch. This parameter specifies the distance between the two centers. If the centers span is equal to the span you obtain an equilateral pointed arch, if it is less than the span you will have a drop pointed arch, if it is greater than the span you will have a lancet pointed arch. 

Apex roundness: this parameter adjusts the roundness of the arch apex. It is advisable to maintain the default value and increase it only for particularly elongated lancet arches (with center span much higher than the span) and when the apex is broken up and poorly defined. In these cases it is also recommended to increase the resolution.    

Materials

While our models come pre-equipped with uv map and materials, you have the freedom to modify or replace them as desired. It's crucial to maintain the correct order of material slots:

1. Arch bricks: material assigned to the arch (the curved part of the arch not the columns).
2. L column bricks: assigned to the left column (ignored if you use a custom column model).
3. R column bricks: assigned to the left column (ignored if you use a custom column model).
4. Wall bricks: assigned to the wall.

By adhering to this order, you can ensure consistency and ease of customisation in your material while maintaining the integrity of the models.  

Limitation and known issues

UV map issues

As already mentioned, the generated models are equipped with a UV map which is also automatically created in a procedural manner. Although we have tried to create a coherent UV map and hide the seam of the map as best as possible, the result may not always be the one desired by the user. In this case it is recommended to transform the procedural model into a "ordinary" model by applying the modifier and then modify the UV map manually.

Materials issues

It is not possible to share the same material on multiple parts of the model (for example, the same material cannot be assigned to the arch and the pillars), this causes an incorrect assignment in the material indices with the corresponding parts of the mesh. You can work around this problem by making a copy of the material.

Subdivision issue with wall

To obtain the empty space of the wall (the internal part of the arch), a Boolean operator is used on the wall mesh. Unfortunately this creates problems if you want to apply the subdivision modifier to the model. The only solution in this case is to deactivate wall generation (by deactivating the “Show wall” flag) and create the wall manually.