TG HeatHaze

PARAMETERS

Note that the Colour version of this shader has all the same parameters. They work in the same way, except for Distortion Amount (which has no effect). The Colour shader is intended as a “preview” shader, to allow you to test various parameters and see the resulting noise and animation movement, as it is faster than having to use Raytracing to get the refractions from the HeatHaze shader.

The following images use a simple cylinder, viewed from above (slight stretched along its Z axis from the default primitive cylinder), which is resting just above a checkerboard plane.

This is to allow you to see the effect that the various parameters have on the result. The cylinder itself is shown in the image on the right.

The cylinder used to produce the test images

The cylinder used for the test images (here rendered with Phong)

Listing :

  Noise Overall Freq
  Noise Octaves
  Noise Type
  Distortion Amount
  Begin Fade
  End Fade
  Faded Distortion Amount
  Fade With Angle Of View
  Fade Direction
  UV / Object / World
  Reverse Angle Effect
  Reverse Fade?
  Frame Offset
  Noise Frequency

Noise Overall Freq

Range : 0 to 100

Sets the overall frequency for the noise, scaling it in all directions equally. Higher values will mean squash the noise pattern, while lower values will stretch the noise pattern.

Noise Octaves

Range : 0 to 10

This controls the Octaves of the noise. Higher values result in more detail in the noise pattern (but will result in the shader rendering more slowly). There is little visible effect in increasing the Octaves above a value of 4 or so

Noise Type

Range : 0, 1 or 2

Sets the type of noise to be used - 0 is Perlin, 1 is Classic, and 2 is Sparse.

Distortion Amount

Range : 0 to 100

Set the amount of distortion caused by the shader. Values are from 0 to 100, and higher values will result in more pronounced distortions.

Distortion of 10

The default settings (distortion of 10).

Distortion of 50

Distortion value raised to 50.

Begin Fade

Range : -100 to 100

The distortion fades along one axis of the object. This is used so that the distortions fade off smoothly further from the source of the heat.

The Begin Fade parameter sets the point at which the distortion begins to fade from Distortion Amount toward Faded Distortion Amount.

End Fade

Range : -100 to 100

The End Fade parameter sets the point at which the distortion reaches the Faded Distortion Amount.

Faded Distortion Amount

Range : 0 to 50

This is the amount of distortion that the effect fades to along the length of the object (the fading being controlled by the Begin Fade and End Fade parameters).

Fade With Angle Of View

Range : 0 to 1

The distortion can be set to fade with the angle between the object surface and the camera. This parameter controls the amount of fade - higher values will cause greater disortions at the edges of the object (that is, when the object point is facing away from the camera rather than directly at the camera).. The fading of the distortion works along the same principles as the transparency fades in TG Glow.

Please note that HeatHaze effects are strongest at the edge and weakest in the centre, because HeatHaze uses refraction to get its effect (this means that where the surface is more steeply angled away from the direction of view, then the effect is more pronounced; where the surface is at right angles to the direction of view, then there is little or no effect).

This parameter lets you increase the overall Distortion effect, allowing more distortion to show up at shallow angles, while reducing the effect at the edges so that it doesn’t become overpowering.

Fade With Angle 0

Distortion 100, Fade With Angle 0.

Fade With Angle 0.6

Distortion 100, Fade With Angle 0.6.

Fade Direction

Range : 0, 1 or 2

The controls the direction in which the effect fades out along the object.

If UV space is used in the UV / Object / World parameter, then a value of 0 causes the effect to fade with U, and a value of 1 causes the effect to fade with V.

If Object or World Co-ordinates are used, then a value of 0 causes the effect to fade with X, a value of 1 causes the effect to fade with Y, and a value of 2 causes the effect to fade with Z (note that the fade always happens along Object Co-ordinates, even when World Co-ordinates are used for the noise).

Note that this is the fading as controlled by Begin Fade, End Fade and Faded Distortion Amount. This has no effect on the direction of motion of the effect, which is controlled independently by  the Frame Offset parameter.

UV / Object / World

Range : 0, 1 or 2

This controls the space used to generate the noise. If set to 0, then the shader will use UV space to calculate the noise (and the fade). If set to 1, the shader will use the Object Co-ordinates to calculate the noise (and the fade), and if set to 2, then the shader will use World Co-ordinates to calculate the noise (and Object Co-ordinates to calculate the fade).

Reverse Angle Effect

Range : On or Off

This reverses the angle effect, resulting in greater disortions at the edges of the object (that is, when the object point is facing away from the camera rather than directly at the camera).

Reverse Fade?

Range : On or Off

This reverses the direction of the fade. Note that the fade will still run along U or V, or x, y or z, but in the opposite direction. Also note that this does not affect the movement of the distortion effect (controlled by Frame Offset).

Frame Offset

Range : RGB values (-10 to 10)

This controls the movement of the noise between frames. The individual values control the shift of the noise in the X, Y and Z directions. Note that when UV space is used in the UV / Object / World parameter,  movement in the Z direction still has an effect.

Noise Frequency

Range : RGB values (-10 to 10)

This lets you scale the noise independently in the X, Y and Z directions. It works in conjunction with the Noise Overall Freq parameter. This parameter lets you stretch or squash the noise in a chosen direction, particularly effective for stretching out the distortions in the direction of movement (as set in the Frame Change parameter).

TG HeatHaze Intro

TG HeatHaze Parameters

TG HeatHaze Tips

TG HeatHaze FAQ

TG HeatHaze Samples

TG Pack Index