VisualShaderNodeTransformVecMult in Godot – Complete Guide

Welcome to our tutorial on the VisualShaderNodeTransformVecMult class in Godot 4, where we dive into the intricacies of shader programming within one of the most powerful open-source game engines available today. Understanding how to manipulate shaders using visual nodes is a fascinating journey that unleashes a myriad of possibilities for game development, enhancing visuals, and creating immersive environments. Let’s embark on a journey together to learn how this specific class can impact your projects and why mastering it can be a game-changer for your development skills.

What is VisualShaderNodeTransformVecMult?

The VisualShaderNodeTransformVecMult is a class used within the visual shader graph of Godot 4. It performs a fundamental operation in computer graphics: multiplying a Transform3D, which is a 4×4 matrix, with a Vector3. This operation is crucial for transforming vectors, which can represent points in space, directions, or other spatial data, according to the transformations represented by matrices.

What is it for?

In the realm of game development and real-time graphics, such multiplications are used to transform object vertices, apply rotations, scale, translate objects in 3D space, or even to combine the various transformations. The VisualShaderNodeTransformVecMult allows you to perform these operations visually within Godot’s shader graph, making shader creation more intuitive and accessible.

Why should I learn it?

By learning how to use the VisualShaderNodeTransformVecMult, you equip yourself with the knowledge to articulate complex visual effects with precision and control. This understanding can be especially useful for creating custom shaders that can dramatically alter the aesthetics of your game or application. Whether you are a beginner or an experienced coder, grappling with this concept opens doors to a deeper understanding of graphical transformations and how they shape the visual experiences in digital environments.

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Creating a Basic Transform Vector Multiplication

To start off, let’s create a simple example of using the VisualShaderNodeTransformVecMult node to scale a Vector3. This is a common task when you want to change the size of an object in 3D space based using a shader.

# First, create a Transform with a simple scale.
var scale_transform = Transform(Vector3(2, 2, 2), Vector3(0, 0, 0), Vector3(0, 0, 0))

# Now, create a Vector3 that represents the point to be scaled.
var point = Vector3(1, 1, 1)

# To perform the multiplication visually, you would create a VisualShaderNodeTransformVecMult node 
# in the Godot Shader Graph and connect a Transform Uniform to it, and a Vector3 Uniform that will be scaled.

# Pseudo code representation of the shader graph connections:
# TransformUniform -> VisualShaderNodeTransformVecMult -> Vector3 output

Once connected in the shader graph, the output Vector3 will represent the point after scaling by the specified Transform matrix.

Applying Rotation Transformations

Rotating objects is another fundamental operation in 3D graphics. We can rotate a Vector3 by multiplying it with a rotation Transform:

# Create a Transform representing a rotation around the Y axis by 90 degrees.
var rotation_transform = Transform().rotated(Vector3(0, 1, 0), deg2rad(90))

# This Vector3 is the point we want to rotate.
var point = Vector3(1, 0, 0)

# In the shader graph, connect the rotation Transform to the VisualShaderNodeTransformVecMult node 
# alongside your vector. The output will be the rotated Vector3.

# Pseudo code representation of the shader graph connections:
# RotationTransformUniform -> VisualShaderNodeTransformVecMult -> Vector3 output

Again, once set up in Godot’s visual shader graph, the output Vector3 variable from the VisualShaderNodeTransformVecMult node would provide the rotated vector.

Combining Multiple Transformations

To illustrate the power of shader transformations further, let’s combine scaling and rotation into one Transform:
# First a scale Transform.
var scale_transform = Transform(Vector3(2, 2, 2), Vector3(0, 0, 0), Vector3(0, 0, 0))

# Then a rotation Transform.
var rotation_transform = Transform().rotated(Vector3(0, 1, 0), deg2rad(90))

# Combine them by multiplying Transforms.
var combined_transform = scale_transform * rotation_transform

# The point to transform.
var point = Vector3(1, 1, 1)

# Setup in the shader graph would be similar; you could use a script or another node to combine the transforms before 
# giving them to the VisualShaderNodeTransformVecMult.

# Pseudo code representation of the shader graph connections:
# CombinedTransformUniform -> VisualShaderNodeTransformVecMult -> Vector3 output

After setting up these nodes in your visual shader graph, you’d see the Vector3 output reflects the point scaled by 2 in all directions and then rotated around the Y axis by 90 degrees.

Transforming Normals for Lighting Effects

Transforming normals (perpendicular vectors to a surface) can be essential for dynamic lighting effects:

# Assuming a normal Transform for lighting calculations.
var normal_transform = some_calculation_to_get_normal_transform()

# A normal to be transformed, typically would be the normal of the vertex in a vertex shader.
var normal = Vector3(0, 1, 0)

# The shader graph connection for normal transformation would be similar to the point transformations, 
# but ensures that the transformations are suitable for normals, like using the inverse transpose of the world matrix.

# Pseudo code representation of the shader graph connections in a Vertex Shader:
# NormalTransformUniform -> VisualShaderNodeTransformVecMult -> Normal output

The resulting transformed normal can be used in a fragment shader for lighting calculations, giving you the correct light reflection according to the transformed surface orientation.

Throughout these examples, replacing the pseudo code with actual connections in Godot’s visual shader graph is a practical exercise that solidifies your understanding of the VisualShaderNodeTransformVecMult node.

Moving forward with our journey through Transform Vector Multiplication using Godot’s VisualShaderNodeTransformVecMult, let’s dive into a few more practical examples that delve into the versatility and power it brings to your shader toolbox.

Translating a Vector: To start with a simple translation, let’s move our point along the X axis:

# Create a Transform for translation.
var translate_transform = Transform().translated(Vector3(5, 0, 0))

# The initial Vector3 point.
var point = Vector3(1, 1, 1)

# Connect a TranslateTransformUniform to VisualShaderNodeTransformVecMult with the Vector3 point in the shader graph.
# The output Vector3 coordinates will now reflect the translation.

Viewport Coordinate Transformation: When working with screen space effects, it’s common to transform viewport coordinates:

# Suppose we have the screen space position.
var screen_pos = Vector3(0.5, 0.5, 0.0) # (in normalized coordinates)

# We can use a camera's projection matrix to convert this to world space coordinates.
var proj_transform = Camera.get_projection_matrix()

# Similar to our other examples, the VisualShaderNodeTransformVecMult would take in this matrix 
# and the screen_pos to output the position in world space.

Model to World Space Conversion: To render objects correctly, we often need to convert their local coordinates to world coordinates:

# The model transform is typically retrieved from the object's transform within Godot.
var model_transform = MeshInstance.get_global_transform()

# Our local point in model space.
var local_point = Vector3(0, 0, 0)

# The shader graph would multiply the model_transform with local_point to achieve world coordinates.

View-Dependent Displacement: For advanced effects such as parallax occlusion mapping, where we simulate depth on a surface, we need to displace coordinates based on the viewer’s position:

# The viewer's position in world space.
var viewer_pos = Camera.get_global_transform().origin

# A vector indicating the displacement direction.
# It can be calculated from a heightmap or similar resource.
var displacement = Vector3(0.1, 0.0, 0.0)

# Now we use our visual shader node to multiply the displacement by a Transform derived from the viewer position.
# This gives us the view-dependent displacement vector.

Mirror Reflections: Creating mirror effects involves transforming points across a reflective plane:

# We’ll define a plane in world space for the mirror surface.
var plane_normal = Vector3(0, 1, 0) # Assuming the mirror is horizontal
var plane_d = 0 # The plane is at the origin

# We create a reflection matrix based on this plane.
var reflection_transform = Transform().looking_at(plane_normal, Vector3(0, 0, 1)).scaled(Vector3(1, -1, 1))

# A world space point that we want to reflect
var world_point = Vector3(0, 10, 0)

# The shader would then use the reflection matrix to transform the point to where it would appear on the other side of the mirror.

These examples demonstrate the breadth of transformations you can perform with the VisualShaderNodeTransformVecMult class in Godot. By mastering it, your ability to craft visually impactful shaders that can simulate a wide range of physical phenomena and optical effects is greatly enhanced. Whether it’s manipulating object positioning, converting coordinate systems, or creating advanced material effects, this class lies at the heart of generating dynamic and convincing visuals in 3D space.

Keep experimenting with these examples and expand upon them. Over time, you’ll find that the VisualShaderNodeTransformVecMult isn’t just a tool but rather a gateway to realizing your creative vision within the ever-evolving canvas of game development and real-time rendering.

Fantastic! Diving deeper into our exploration of the VisualShaderNodeTransformVecMult, we’ll explore a greater scope of practical examples where this node can be used to achieve various graphical transformations and effects in Godot. Ready your minds for a further set of enlightening shader programming snippets!

Animating Vertices: We can use the VisualShaderNodeTransformVecMult to animate vertices in a vertex shader:

# We'll define a sine wave based Transform for vertical oscillation.
var time = OS.get_ticks_msec() / 1000.0
var sine_wave_transform = Transform().translated(Vector3(0, sin(time), 0))

# The vertex we want to animate.
var vertex = Vector3(1, 0, 0)

# In the shader graph, we'd multiply the vertex by this animated Transform to make it move up and down.

Scaling Textures: Texture coordinates can also be transformed to achieve various texture scaling effects:

# Let's scale a texture by half its size.
var uv_scale_transform = Transform(Vector3(0.5, 0, 0), Vector3(0, 0.5, 0), Vector3(0, 0, 1))

# These are our texture's UV coordinates.
var uv = Vector2(0.5, 0.5)

# We extend the UV vector to a Vector3 for the Transform multiplication, effectively applying the scale transformation.
# We only use the x and y components of the result as the new UVs.

Bending Geometry: To bend or warp geometry, such as creating a flag waving effect, use transformations:

# We'll use a Transform to apply a curvature based on the sine of the vertex's x position.
var vertex_position = Vector3(1, 0, 0)
var bend_amount = sin(vertex_position.x) * 0.1
var bending_transform = Transform().rotated(Vector3(0, 0, 1), bend_amount)

# The vertex position is then multiplied by this bending Transform.

Instancing Transformations: When instancing objects with different transformations, we can use an array of transforms:

# For example, we have a Transform array for multiple instances.
var transforms = [Transform().translated(Vector3(0, 0, 0)), 
                  Transform().translated(Vector3(1, 0, 0)), 
                  Transform().translated(Vector3(2, 0, 0))]

# Each instance vertex can then be multiplied by its corresponding Transform.
var instance_id = some method to determine the current instance ID
var vertex = Vector3(1, 0, 0)

# The final position would be calculated in the shader graph by selecting the right Transform from the array.

Billboarding: To create a billboard effect, where objects always face the camera, use transformations to orient the geometry:

# The camera's global transform.
var camera_transform = Camera.get_global_transform()

# We want to create a billboard that always faces the camera.
var billboard_transform = camera_transform.looking_at(some_object_position, Vector3(0, 1, 0)).inverted()

# The geometry's vertices would be multiplied by this billboard Transform for proper orientation.

Through these varied scenarios demonstrating the use of VisualShaderNodeTransformVecMult in Godot, you can envision how transformative (pun intended!) this node can be for your visuals. It may be clear by now that this node is more than just a utility; it is a podium on which the art of shader programming performs—an artist’s brush, a mathematician’s compass, all rolled into one. Every vertex, vector, and visual effect that passes through this node is sculpted by the mathematics and logic wired into Godot’s powerful visual shader graph.

Embark on this journey through shader programming with these examples as stepping stones. With each step, your mastery grows not just in Godot 4 but in the understanding of how visuals come to life in any 3D game engine. And remember, whether you’re scaling textures, animating vertices, bending geometry, instancing transformations, or ensuring objects face the camera, the VisualShaderNodeTransformVecMult stands as a reliable tool in your developer toolkit, opening up a world of creative potential.

Where to Go Next in Your Godot Journey

Your exploration of the VisualShaderNodeTransformVecMult in Godot 4 does not have to stop here. We at Zenva encourage you to keep fueling your passion for game development and to harness the full potential of Godot – an engine that paves the way for both novices and seasoned developers alike. The journey of learning continues with resources that can further broaden your understanding and skill set.

Consider delving into our Godot Game Development Mini-Degree, a comprehensive series of courses tailored to take you through the ins and outs of building cross-platform games with Godot. Our curriculum doesn’t just cover the basics; it encompasses a variety of game development facets from 2D and 3D assets to UI design, allowing you to build your own games from scratch.

For those looking to dive even deeper or explore other areas of Godot, check out our broader collection of Godot courses. With these resources at your fingertips, the path to achieving real-world results, such as publishing your own games or venturing into a career in the industry, is within reach. Keep learning, keep creating, and let Zenva be the companion on your journey to mastering Godot and game development.

Conclusion

As you’ve journeyed through the compelling world of the VisualShaderNodeTransformVecMult in Godot 4, we hope you feel inspired by the breadth and depth of possibilities it opens up in your game development adventures. Remember, mastering tools like these propels you not merely towards completion of a task, but towards the realization of your most imaginative creations. The nodes and networks you’ve seen here are just the beginning; they are brushes set on the canvas of Godot, ready for you to command them and bring your visions to life.

Whether you’re a curious beginner taking your first steps, or an experienced dev leveling up your skills, Zenva has got you covered with high-quality content designed to teach the ins and outs of game creation. Explore our Godot Game Development Mini-Degree to start shaping your dreams into playable realities today. Unleash your potential and let’s craft remarkable experiences together. Your journey awaits!

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