Introduction to Flow Properties
The unique feature of Flow addon is the possibility of adding easy custom properties for the objects, so the various assets elements may be modified without the need of digging in the shader editor or making the object editable in the case of e.g. Collection Instances. Thanks to the property system, the selected values may be tweaked with the sliders directly in the Flow N-panel. This is really easy to use and with Flow 2.70 made even easier for the material properties.
Adding new properties
NEW FEATURE – FLOW 2.70 – Material Properties – Property Node Groups
In Flow 2.70, we’ve developed the amazing feature to create and manage the properties for the materials much easier and without any multi-users issues. From now on, you do not need to connect each single property separately as the driver to the material inputs, but create the special node group, of which all the inputs will be shown in the properties section of the Flow panel.
Creating the Flow property node group is quite similiar to creating the regular node group. Go to the shader editor and select the nodes, that you’d like to group. Then, instead of clicking CTRL+G, click CTRL+ALT+G. In the popup window, type your desired group name. If you are converting single node, like Principled BSDF, it’s recommended to mark Clear Group Inputs, as in this case, all the nodes inputs will be converted into the node group inputs, what can make the group a little bit more difficult to use.
Then, when the group is created, simply connect the desired nodes inputs into the Group Input node sockets – they will appear in the Flow panel in the 3d Viewport. Customize it your own way, making the properties quickly and easily.
The standard way to add the properties is to create them in the Flow panel. When the editable object is selected, you may start adding custom properties for it. What you may modify with it? Actually almost any editable value in Blender!
Creating the property
When you create the property, you need to know what value are you going to tweak it with. It is important, as you need to set up min and max values. So when you are going to connect it to the slider with values 0.0 – 1.0, it is recommended to create the property with the same range as your target property.
Connecting the property
In this short example, I’ll show you how to manipulate the object’s size, using shape keys and Flow properties. First, let’s create a cube – it will be the easiest object to show this system.
When the cube is created, go to the Mesh Properties. Now create some shape keys, by clicking + button in the Shape Keys section. Firstly, Basis key will show up and this one represents the initial shape of your mesh. In this example, we’ll leave it untouched.
Now create another shape key, and one with the value will be added to the list, and this one is the one important for us, as it will store the shape changes in it’s value 0-1 (where 0 means the initial / basis shape and 1 means the modified shape of the mesh). Select the newly added shape key and enter the edit mode with TAB
Grab one of the cube’s faces and move it anywhere. Notice, that you are not able to do anything with the shape key’s value in the Edit Mode. This is, because you are now creating the shape for that will be represented by value 1.0. When you are ready, go back to Object Mode and now play a little bit with your shape key’s value. As you see, when you are moving the slider, the shape is changing smoothly from the basis shape to the shape you’ve made in the edit mode.
I’ll stop talking about shape keys at this point, as this is much enough you should know for this tutorial, if you are willing to learn more, there is a plenty of amazing tutorials on Youtube.
Now it’s the right time to create our custom property. In the Flow panel find the Properties section and click ‘Add New Property’. In the popup window, type the name that you want for this property, and set up the Min and Max value for 0 and 1 (as the shape keys values are by default 0.0-1.0)
When the property is added, it should show up as the slider in the Properties section of the Flow panel. To connect the property to the target slider, right click on the property slider and in from the menu select Copy as New Driver.
Now go to the shape keys list, select your ‘Key 1’ and again right click on the value slider. Select Paste Driver and from this moment, your custom property is connected to the shape key value.
What is important – when you are using drivers, target slider will not be able to tweak the value. You can do that only from the source of this driver, so in this from the property. The driven value is always marked with the purple field. If you want to disconnect the driver, just right click on the purple slider and select Delete Driver.
Always remember, that properties added with the panel, are strictly connected to the active object. So if you will connect it to any value, that is also linked to another users (like for example any material inputs), unexpected results may occur. This was the old approach, but from Flow 2.70, in the case of materials, it’s now much better to use very new Property Node Groups, to avoid any unexpected issues. This new approach is described below.
Managing the properties
Managing node groups is quite simple. Change group inputs if you want to modify, what is to be shown. If you want to remove the group completely from the panel, but you’d like to keep the group in the material, simply remove FLOW_ prefix from the group’s name and that’s all.
In case of regular proeprties, added with the panel, you are able to modify or remove each of the added property. To modify the property, click on the gear icon to see the settings popup. There, you can modify type, min and max values, softmin, softmax, step, precision, name (remember to keep the DA_ prefix!)
To remove the property, just click on the X icon on the right, but mind that this operation does not remove drivers from your object properties, so you’ll have to remove them by hand. This is caused by Blender limitations.
But, when you click Apply Properties, the changes will be ‘written’ into your object, and all the drivers will be removed. Also by applying Flow properties, all shape keys will be removed. This operation will not influence node groups, only the standard object custom properties
Using properties with different types of instances
Using properties is slightly different, when you are working with regular editable objects and with collection instances, that are the default type of asset, that you will be placing with Flow.
With the editable objects, the matter is simple. Properties shows only for the active object, you can then edit them, modify, remove etc. One object, one set of properties.
All changes, when you are working with instance collection. When you click on this kind of asset, only the sliders will appear, no possibility of modifying or removing props directly. Of course, that is still possible, but to do that, you’ll need to edit this instance collection (possible with Flow Edit Local Instance operator). Then, when instead of single instance collection, you can see edit your properties for each object. And when multiple objects within this one collection will be using properties, Flow will gather all of them as one set.
Actually, collection instances are quite interesting type of Blender object, and I’ll write another article about them, as using them may to facilitate your work and improve your scene’s performance. They also help to decrease the filesize.
I hope that you now understand Flow properties better and you are also able to create your very own properties for your assets.