Mental Ray Water Surface

Skill Level: Beginner to Intermediate

Time to Complete: 20 Minutes

Introduction

This tutorial will guide you to achieving a fairly realistic open water effect which can even be animated, using the 'Ocean' shader from the Lume Library.

Set Mental Ray as the rendering engine. Hit F10 to bring up the Render Setup dialogue box. Go to the Assign Renderer rollout in the Common Tab. Open it and set Mental Ray as the Renderer (Fig.01).

Fig.

Fig.

Go to the Units Setup dialogue box under Customize Menu. Set Metric as the Display Unit Scale and Meters as the default unit (Fig.02).

Fig.

Fig.

Create a Plane at the origin with dimensions of 10 m x 10 m. Set Scale to 10 under Render Multipliers. Rename it as 'Water Surface'. Create a Target Direct light (under Standard Category) and place it at X = 2 m, Y = 4 m and Z = 6 m. Place the Target of the light at X = -1.5 m, Y = 0 m and Z = 0.75 m. Set Shadows to Ray Traced Shadows. Check 'Overshoot' under the Directional Parameters. Create a Target Camera and place it at X = -7 m, Y = -9 m and Z = 6.25 m. Place the Target of the Camera at X = -0.175 m, Y = -1.125 m and Z =- 0.9 m.

Hit M to call up the Material Editor. Click on the 'Standard' button on the top right hand corner. The Material / Map Browser opens and select 'Arch & Design (mi)' (the top most entry) as the material type*. Rename the material as 'Water Surface' and assign it to the plane (Fig.03).

Fig.

Fig.

Under 'Main material parameters' change Color in the Diffuse section to R = 0.439, G = 0.522 and B = 0.486. Set Reflectivity to 0.7 in the Reflection section (Fig.04).

Fig.

Fig.

Open the 'Special Purpose Maps' rollout and click the button next to the Bump parameter. The Material / Map Browser opens. Select 'Ocean (lume)' as the bump map (Fig.05)

Fig.

Fig.

Set the parameters of the ocean shader as follows (Fig.06):

  • Largest = 0.25m
  • Smallest = 0.005m
  • Quantity = 5
  • Steepness = 6.25
  • Plane Distance = 25 m
  • Directed = Yes
  • Direction angle =150
  • Wave Speed = 0
  • Flats = No

Fig.

Fig.

Hit 8 to call up the Environment and Effects dialogue box. Click the Environment Map button under the Background section. The Material / Map Browser opens. Select Gradient (Fig.07).

Fig.

Fig.

Hit M to call the Material Editor. Drag the Gradient map created to an unused slot of material editor. Check 'Instant' radio button (Fig.08).

Fig.

Fig.

Open the 'Gradient Parameters' rollout and set following parameters (Fig.09):
 Colour#1:  R = 242, G = 245 and B = 253
 Colour#2:  R = 107, G = 130 and B = 248
 Colour#3:  R = 194, G = 191 and B = 183
 Colour 2 Position:  0.2

Under the Coordinate section check 'Environ' and select 'Spherical Environment' in the 'Mapping' drop down list. This replaces the default 'Screen' projection (Fig.10).

Hit F10 to call Render Settings dialogue box. Set the Output Size to 35mm 1.66: 1 (cine). Set the Width and Height to 1024 x 614 (Fig.11).

Fig. 11

Fig. 11

Set the active view to Camera 01. Turn off any Final Gather or GI and hit F9 to render the camera view (Fig.12).

Fig. 12

Fig. 12

In case you need to use FG or GI or both, for example, in conjugation with mr Physical Sun & Sky, set the Diffuse Level under Diffuse section to a lower value, such as 0.25 or so. In reality, the water has no diffuse characteristics; it is seen only due to the light that is reflected from and refracted through it. Higher Diffuse values cause water surface to be over lit when trying to simulate the reality using FG or GI. For any surface, the following relationship exists: Diffuse + Reflection + Refraction = Total Light Remitted from the surface. This is in agreement with the first Law of Thermodynamics which states that the total energy received by the surface is the sum of that absorbed and transmitted. Thus, no light is permitted to be created spontaneously.

Camera View Rendered

Arch & Design (mi) Material is available only in Mental Ray 3.5 and later (i.e. 3ds Max® 9 and later). If you are using older versions follow this alternate procedure:

Select 'Architectural' (1st entry from top) as the Material Type from the Standard button. Enter the R = 112, G = 133 and B = 124 values for the diffuse colour and 75 for the 'Shininess' under 'Physical Qualities' Rollout. Assign a Ocean (lume) shader with the same parameters to the 'Bump' Slot in 'Special Effects' Rollout.

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