UE4 – Bump Map

Software:
Unreal Engine 4.21

To use a ‘Bump Texture’ in UE4, or in more geeky terms, derive Normal data from a supplied height map, use the NormalFromHeightMap Node.

Notes:

  1. The height map textured is supplied via Texture Object node and not Texture Sample, and is connected to the NormalFromHeightMap‘s Height Map input.
  2. A numeric vale is connected to the NormalFromHeightMap‘s Normal Map Intensity input to control the intensity of the resulting Normals/Bump.
  3. UV coordinates for the bump map should be connected to the Coordinates input of the NormalFromHeightMap node.

bump

 

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VRayMtl’s new metallic goodness

Software:
3ds max 2019 | V-Ray Next | V-Ray next GPU

In V-Ray Next (4) for 3ds max, a new Metalness parameter has been added to the Reflect parameters of the VRayMtl material.
This allows for easy creation of realistic metal materials and also effectively enables a PBR workflow with V-Ray.

When the Metalness parameter is set to 1.0, the material becomes completely reflective, the Diffuse color controls the general reflection color, and the Reflect color (which should generally be set to white) controls the reflection color at grazing incidence angle.

The IOR parameter still controls how fast will the main reflection color (set by the Diffuse color) blend into the Reflection color, and I don’t know whether some form of complex Fresnel has been implemented or if it’s just a dielectric simple Fresnel blended over a reflective surface.

An excellent article on the new Feature from the Chaos Group blog:
https://www.chaosgroup.com/blog/understanding-metalness

VRay_Next_Metalness

Related:

  1. Fresnel Reflections
  2. Complex Fresnel for Blender & Cycles
  3. Metal material in UE4

 

Randomize textures in V-Ray for Maya

Software:
Maya 2018 | V-Ray 3.6

Connect the different texture options as inputs to a VRayMultiSubTexNode and connect it to the wanted material input.
In the VRayMultiSubTexNode attributes, set Get ID From to Random by Render ID.
* Press add new item in the VRayMultiSubTexNode attributes to add one or more inputs to the list.

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Create a richly colored metallic surface in UE4

Software:
Unreal Engine 4.18

One of the optical properties of many metallic surfaces is changing it’s color slightly as the surface viewing angle changes.
This effect can be simply created using a Fresnel node and a color-ramp texture.

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  1. Create a metallic material (metallic value of 1.0).
  2. Use an image editing software to create a linear color ramp texture (gradient) of the color change per viewing angle from left to right. like this example for a golden metal, and import it to your project.
    Ramp_Gold
  3. Add the ramp texture to the material Blueprint, and connect it to the material Base Color Input.
  4. Create a Fresnel node and set its Exponent value to 1.0 and its Base Reflect Fraction to a value of 0.0 so it will provide a linear angle blend value.
  5. Connect the Fresnel node’s output to the UVs input of the ramp texture node.
    * the reason the Fresnel node can be providing both the X and Y texture coordinates is that the texture’s Y dimension provides the same color for all values anyway.

Note:
When the Metallic property of an Unreal Engine material is set to 1.0, the material automatically simulates the metal’s color fading to white at parallel surface viewing angle (the sides) like it should.
So using a Color Ramp Texture like in this example creates an amplified effect.
* Simply put: You don’t have to have the Color Ramp fade to white on the right side of the texture..

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UE4 – Material Transform Vector Node

Software:
Unreal Engine 4.18

The Transform Vector material node transform the supplied vector between different geometrical spaces according to your choice:

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Note:
This is useful in order to convert surface normals from Tangent Space to World Space to connect them as input to a Fresnel Node.

Using VRayMtlHair3 shader with nHair in Maya

Software:
Maya 2018 | V-Ray 3.6

  1. Select the nHair object.
  2. In the Attribute Editor, in the hair system shape attributes.
    Open the Attributes menu, and choose VRay > Hair Shader.
  3. Create a VRayMtlHair3 shader.
  4. Connect the shader to the Hair Shader slot under VRay Extra Attributes in the hair system Shape Node attributes.

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Related:
V-Ray for Maya and XGen