Input Adaptive Math Node

Problem

When working with Shaders, we often have to perform math operations on vectors . The current nodal interface in blender deals nicely with operations on values, however operations on vectors are very inconvenient. As you know, when you connect a vector or color to Math Node , it will be automatically converted to a value and the operation will be performed on this value. We do not have a dedicated node that allows us to perform any mathematical operations on vectors and colors (MixRGB only support few of them). Currently, the only method to do it in Blender is to separate vector into 3 values, perform math operations on them in parallel and then combine them into a new vector. Technical artists who work with other nodal systems certainly know that the blender solution is cumbersome and slow. In addition, networks created in this way are more difficult to compile and have lower performance!

Solution

Most programs that use nodal systems have a much better solution. Input Adaptive Nodes . Principle is simple, if you connect values ​​to the node, it performs the operations on values and output is a value. If you connect vectors, node performs component wise operations on vectors and output is a vector. Many systems allow you to use a vector in combination with a value. This allows uniform scaling using multiplication, division of space into equal cubic cells by means of the Round operation, etc.

I propose to implement Input Adaptive Math Node in Blender. This solution will greatly improve work with shaders. I think we need that for Nodify Everything project in order to work efficiently with vectors.

You're probably wondering about backwards compatibility or what if you WANT to turn vector into value. Let's start from scratch.

1. Input sockets in Math Node should be colored white . This will suggest a new type of input socket - the Adaptive one, when input slots are empty, it works like current Math node. User can specify values ​​in input fields and node perform operation on values.
2. When a Value is connected socket changes color to gray. The rest works above.
3. When a Vector / Color is connected. Node performs component wise operations on vector / color and output is a vector / color. Sockets changes color to purple or yellow accordingly.
4. If you want to convert Vector / Color into Values ​​(like it works now automatically) you can enable new "Convert Inputs" option. This will be needed to preserve backward compatibility with existing shaders. When loading old scenes, the option should be turned on automatically in all math node instances. On new scenes I propose to turn off by default.
5. When Vector and Color are connected to node output type is same as first input type.

See the table of possible input combinations and gif with examples below.

"Why not just Vector Math Node?"

We could add missing math operations to Vector Math Node and call it a day. In other nodal systems each math operation is a different type of node. The strength of Blender's Math Node is the ability to perform various types of operations with only one node. To add next operation, you simply copy the node, link it and change the type of operation. It's much faster than searching for specific node in the menus or typing in search field. What's more, if you want to completely change the sequence of operations, you don't need to reorganize the entire node tree. Just change the types of operations (even faster using CTRL+Scroll), adjust your values, done! It encourages us to experiment. This method of interaction and the fact that nodes display the values makes workflow much faster than in other systems. However, as I mentioned, this applies only to operations on values. Here is the issue with Vector Math Node. If we simply add the missing mathematical functions to it, we will need to use 2 types of nodes at the same time, like in other systems. This will result in much slower workflow. Two steps forward, one step back. I believe that with the correct implementation of Input Adaptive Math Node we will get the best possible nodal interface!