MatCapMaterial_v3 Op
Easy to use image based lighting Material
Summary (oneliner)
In 3D computer graphics, the appearance of an 3D object depends on several things:
the surface normals (which determine how the object is shaded); the point from which the object is viewed; the lighting setup (orientation and types of lights); and how the surface reacts to that lighting (for example, how shiny it is). MatCap (Material Capture, also known as LitSphere) are complete materials, including lighting and reflections, so you can add it to an object and not have any need for, well, lighting and reflections. MatCaps allows you to create a surface material and lighting environment simply by painting an object so that it looks like how you want your surface to appear. This opens up all sorts of interesting possibilities for non-photoreal image rendering.
The key to using a MatCap texture is that is is mapped to the object’s normals (which exist in relation to the camera) defining a color for every vertex normal direction relative to the camera, and your material is set to shadeless (because you don’t need lights to have any influence, as they are a part of the MatCap texture). So as the camera moves around the object, the reflections and highlights move around your object (as if the object were moving and not the camera). In other words, if your object were a sphere, no matter how you looked at it, it would look like the matcap sphere (reflections always in the same place, e.g.). But as your object takes non-spherical shapes, thus changing the normals, the material responds as if it were made of the complex material.
MatCap is most commonly used for sculpting, as it gives quick and useful feedback on how an objects shape is changing. It also works with rendering, to an extent (good when you need to do a quick show-off-your-model render and don’t have time to set up any complex lights or materials). It's very cheap, and looks great when the camera doesn't rotate.
Text taken from https://github.com/nidorx/matcaps
Be sure to check out the repository to find a huge archive of matcaps!
Use at your own risk :)
- Ops.Gl.Shader.MatCapMaterial_v3
- Core Op - Official cables op
- MIT
simodDocumentation (markdown)
Issues
Example patch id
Youtube ids (comma seperated)
Op Licence
Caniuse query
INPUT PORTS
trigger input
matcap texture input
Texture Maps
diffuse texture input
normal map input
specular mask input
specular matcap input
AO texture input
opacity texture input
Color
R channel of diffuse color
G channel of diffuse color
B channel of diffuse color
Alpha channel of diffuse color
Texture Transforms
Intensity of AO texture
Intensity of Normal Map
Texture Repeat along the x-axis
Texture Repeat along the y-axis
Texture Coordinate offset along the x-axis
Texture Coordinate offset along the y-axis
Normals
check to use screen space normals (flat shading)
calculate normals & tangents
Texture Opacity
invert y-axis of opacity texture texture coordinates
discard transparent pixels under a threshold of 0.2
switch to choose which channel of the texture should be used for alpha mapping
OUTPUT PORTS
output trigger
shader output
