VRay Material VRay Mtl Reflection Lesson Introduction Orientation

V-Ray Material: VRay. Mtl Reflection

Lesson Introduction – Orientation • This presentation will take you through setting up reflections for a basic material • This information centers around the main Reflection parameters for VRay. Mtl • The lesson topic is approximately 30 minutes in length • Presentation covers all 3 Learning Cycles for the Lesson Topic – Lecture, Demonstration, and Activity

Lesson Topic: V-Ray Material Reflection • Objective – We will use several parameters to create and alter a material in the scene • Develop the look for the owl statue • Use various reflection parameters to create different looks • Outcome – You will understand how to work with the Reflection parameters in VRay. Mtl to create a specific look

Lecture: Terminology • Here are some terms to be aware of when thinking about reflection – Reflection – Image reflected in a surface from environment – Highlight – Reflection of a light source, same color and shape as light source – Anisotropy – Elongation of reflections and highlights – Fresnel – Algorithm that varies light behavior based on the angle at which light bounces off the surface

Lecture: Reflections in the Real World • In life: • Shininess depends on smoothness and composition of a surface material • Reflected image shows the environment • In V-Ray: • Shininess is set by a material’s reflection parameters • Reflected image can be a map assigned by user • In both: • Highlights (called Specular) come from light sources being reflected in a shiny object

Lesson Topic: V-Ray Material Reflection • Reflection Overview • Increasing Reflection Color slider to make the color brighter makes a surface appear smooth and shiny • Lights in a scene generate highlights on shiny surface called Specular Highlights • Reflected environment can be set with a map, with HDR images being very popular to use as reflection maps • Maps (such as glossiness, bump, displacement, etc. ) can add imperfections to a surface to enhance the realism of reflections

Lesson Topic: V-Ray Material Reflection • Attributes that affect a reflection’s appearance • • • Reflection Color Reflection Glossiness Hilight Glossiness Use Fresnel Anisotropy

Lesson Topic: V-Ray Material Reflection • Reflection Color • Hue determines the color of reflections • Luminance (slider) determines level of shininess • Amount acts as multiplier for shininess • A texture mapped to Reflection Color and/or Amount adjusts the amount of the reflection on the surface; i. e. creating areas of more or less shine, or different in the color of shininess

Lesson Topic: V-Ray Material Reflection • Reflection Glossiness • Sets sharpness/fuzziness of reflections • 1. 0 is perfect mirror, lower is more “glossy” • Reflection Glossiness is locked to Hilight Glossiness by default. • Hilight Glossiness sets sharpness/fuzziness of highlights

Lesson Topic: V-Ray Material Reflection • Use Fresnel • Makes variations in reflections based on angle of normal • Adds realism to curved surfaces • Refraction IOR affects degree of variation

Lesson Topic: V-Ray Material Reflection • Brdf - Bidirectional reflectance distribution function • Algorithm for highlight and reflection generation • Each makes a surface appear to be made of different materials Phong Ward

Lesson Topic: V-Ray Material Reflection • Anisotropy • Degree to which highlights are elongated • Anisotropy Rotation parameter turns the elongated highlights

Lesson Topic: V-Ray Material Reflection • Render elements • Reflection settings affect reflect and specular render elements • Here we see just the reflections (left) and just the specular highlights (right)

Lesson Topic: V-Ray Material Reflection • Realism with textures • Nothing in life is perfectly smooth and shiny! Objects have dents, dings, scratches, smudges, etc. • Scratch/dent maps add realism to shiny materials • Grayscale maps adjust the amount of reflection as well as the glossiness of reflections to create variations in the surface

Lecture Conclusion: V-Ray Material Reflection • Reflection Color – Sets overall reflected color or pattern • Reflection and Hilight Glossiness – Sets sharpness/fuzziness of reflections and highlights • Fresnel – Adds realism by altering light behavior over curved surfaces • Anisotropy – Elongation of highlights and reflections

Time to see it work! • Demonstration Cycle! • Watch while I demonstrate how to set up reflection for a basic VRay. Mtl material

Time to do it yourself! • Activity Cycle! • Now it’s your turn!! • Use the provided scene file to set up a reflective material for the owl • The next slide provides some specific values I used for your reference

Dealing in the right values • • • Reflection Color – medium gray Brdf – Ward Reflection Glossiness – 0. 7 Use Fresnel – On, Fresnel IOR – 20 Anisotropy Rotation – Carbon_Reflect 05. jpg