Material Behaviour

Material Behaviours are a way to encapsulate shader functionality into building blocks. These building blocks can then be reused across multiple TGorillaDefaultMaterialSource components. This makes it easy to keep your shaders organized and maintainable.

NOTICE: Material behaviours are not compatible with embedded Firemonkey material sources, like TLightMaterialSource or TColorMaterialSourcce!

Apply a single material behaviour to multiple material sources, but the place to edit parameters of your behaviour stay centralized. This makes it very easy to manage complex shading behaviour.

Think of material behaviours as a collection of shader snippets which can be inserted into other shaders. For each behaviour you can write code for vertex and fragment shader.

This way, to build complex material surroundings, was developed to give users an easy way to setup a GPU based wind system or to render water caustics across different 3D objects.

In many sceneries you might have large number of different types of materials and you don't want to write the same shader function for each of them. Instead you want a central component to control parameters of your behaviour and apply it to the materials you like.

This way of building shader blocks became very handy, so we've started to implemented more components. The most flexible one is of course the TGorillaMaterialDesignTimeBehaviour which allows to setup a materials behaviour at design, also with it's parameters.

At the beginning we offer a few prepared components for you:

A material behaviour is attachable to TGorillaDefaultMaterialSource components. You can either attach those by the designtime property “Behaviours” of the default material source component or use the embedded methods for managing your material behaviours.

The TGorillaMaterialBehaviour class is the basis for all kinds of material behaviours. It offers a number of abstract methods to control the integration of a behaviour.

Besides the overwritable methods to control the behaviour integration the component provides a few callback event properties:

The design time material behaviour component allows you to create material behaviours right in your IDE without writing a new component class.

Many shaders might need parameters to control their rendering. To supply values for those, we will need a unique uniform buffer.

The design time material behaviour provides an easy to use structure called “TDesignTimeUBO” to manage your parameters. It's a simple collection DesignTimeParams inside of your TGorillaMaterialDesignTimeBehaviour component.

Each item is of the type TDesignTimeUniform with the following configurable properties:

The design time behaviour component will try to set up an OpenGL std140 memory layout compatible structure automatically for you and push it to the shader program.

NOTICE: You don't have to take care of any adjusted allocations.

Using the InputValue property in IDE expects a compatible string input corresponding to the selected DataType and Layout of your uniform parameter:

The wind material behaviour is a global component to be applied to default material sources, which should be affected by waving wind functionality.

Our wind behaviour is based on a wind channel, which is defined by a source point and a direction from there. The width, height and distance properties define the size of the channel. The wind is strongest at the source point and along the channel axis. It will lower its intensity to the outside.

The wobble material behaviour enables additional code in the vertex shader of each attached default material source.

It modifies the vertex position randomly by a noise function to simulate wobbling. This effect might be useful for waving or droplet simulation.

By the following properties you can control the behaviour yourself:

For the rim lighting behaviour we've extracted the shader functionality from the TGorillaRimLightMaterialSource component to make it accessable to all default materials.

A rim light is placed behind a subject that exposes the outline or rim of the subject with light. This lighting highlights the contours of a subject and creates a dramatic and mysterious effect.

Rim lights can be used in a variety of ways. They can be used alone as a rim lighting setup to create a high contrast, stylized image. They can also be used in conjunction with other lighting setups such as the traditional 3 point lighting setup. When used in other lighting setups, these lights are often referred to as “hair lights” or “halo lighting.”

https://www.studiobinder.com/blog/what-is-a-rim-light-photography-definition/

Caustics are a well known optical effect produced by water surface. It's a light reflection effect, which we simplified and implemented as material behaviour.

Is a very simple material behaviour to adjust output colors of attached material sources by controlling brightness, contrast, gamma, hue, saturation and luminosity.