Using Custom Shader Operators

Custom Shader Operators combine TiXL preset system with its shader pipeline to provide a very powerful and fun method to create useful custom operators.

Preface

TiXL has hundreds of ops and effects. But at certain level it is no longer feasible to create new parameters for every single edge case. This is where custom shader ops come into play.

As of v4.1 TiXL has:

• [CustomPixelShader]
• [CustomPointShader]
• [CustomForce]
• [CustomVertexShader]
• [CustomFaceShader]

You don't need to understand or write shader code to use these. Just open the preset window, create or select the Custom Shader op and experiment with the presets. Each of the ops come with a set of parameters Offset, A,B,C,D that can be used by the shader fragments. Ideally they should give some comments of what does what.

TODO: Add more details

Writing Shaders

TODO: Add more details

Built-in helper functions

Name	Description	Parameters
Biased	Applies the GainAndBias remapping	float value
SampleGradient	Samples the color gradient at the giving position	float value

Using Quaternions

Name	Description	Parameters
qMul	Performs standard Hamiltonian product of two quaternions.	float4 q1, float4 q2
qRotateVec3	Rotates a 3D vector by a quaternion using an optimized formula.	float3 v, float4 q
qConjugate	Returns the conjugate of a quaternion (negates the imaginary part).	float4 q
qInverse	Calculates the inverse of a quaternion.	float4 q
qFromAngleAxis	Creates a quaternion representing a rotation of angle around axis.	float angle, float3 axis
qFromVectors	Creates a quaternion representing the rotation from v1 to v2.	float3 v1, float3 v2
qLookAt	Creates a rotation quaternion that points toward forward with specialized up.	float3 forward, float3 up
qSlerp	Performs Spherical Linear Interpolation between two quaternions.	float4 a, float4 b, float t
qFromEuler	Converts Euler angles (yaw, pitch, roll) to a quaternion.	float yaw, float pitch, float roll
qToMatrix	Converts a quaternion into a $4\times4$ rotation matrix.	float4 quat
qFromMatrix3	Simplified conversion from a $3\times3$ matrix to a quaternion.	float3x3 m
qFromMatrix3Precise	Robust conversion from a $3\times3$ matrix to a quaternion (handles all cases).	float3x3 m