Show in Contents
Add to Favorites
Home: Autodesk Maya Online Help
Open the scene for the lesson
Lesson 5: Caustics
Render the scene using caustics
Render the scene using raytracing
To better understand the differences between
caustics versus other lighting, you begin by rendering the scene
using the mental ray for Maya renderer without using Caustics.
You start by preparing the scene and then rendering.
In this section you:
- Set
a panel layout for rendering
- Turn
on shadows for the spotlight
- Turn
on the mental ray for Maya renderer
- Set
the image size for your rendering
- Set
the image quality preset
- Render
the image using raytracing
Setting a panel layout for rendering
Producing a rendered image usually requires
that you render test images to achieve the final result. This may
involve adjusting many render quality, shading, and lighting settings.
Opening and closing the various windows can become tedious.
Keeping the most frequently used windows and
panels open allows you to work more efficiently.
In the following steps, you select a panel layout
to work more efficiently with the various panels and windows.
To
set a panel layout for rendering
- From
the perspective view’s panel menu, select Panels > Saved Layouts
> Hypershade/Render/Persp.
The
panel layouts update to display the Hypershade window, Render
View window, and Perspective view
simultaneously.
When you render an image, it appears in the Render
View window.
TipYou can resize the panels in a preset layout
by dragging the border between neighboring panels using your left
mouse button.
Turning on shadows
In this lesson, you learn how the bottle’s shadow
can be made to appear more realistic as a result of the caustics.
To
turn on shadows for the spotlight
- In
the Hypershade window, click the Lights tab.
The Hypershade displays
icons for the two lights in the scene.
- In
the Hypershade window, double-click
the icon for spotLightShape1.
The Attribute Editor appears.
- In
the Attribute Editor, click the
spotLightShape1 tab to display the lighting attributes for the spotlight.
- In
the Shadows section, open the Raytrace
Shadow Attributes and turn on Use RayTrace Shadows.
When you render the scene, shadows are cast
by the spotlight.
- Hide
the Attribute Editor by clicking
the Show/Hide Attribute Editor icon on
the Status Line.
Using the mental ray for Maya renderer
To
use the Caustics feature in Maya you must render using the mental
ray for Maya renderer.
To
turn on the mental ray for Maya renderer
- In
the main menu, select
Window > Rendering Editors > Render Settings (or
click the Render Settings icon in the Render
View window).
- In the Render Settings window,
set the Render Using setting to mental ray.
Setting the image size for rendering
You set the size that an image will be rendered
in the Render Settings window. For
this lesson, you render the image at a size that allows you to evaluate
the caustic effect.
To
set the image size for rendering
- At
the top of the Render Settings window, select
the Common tab and open the Image
Size settings.
- Choose
the 640 X 480 preset from the Presets drop-down
list.
Setting render presets for raytracing
For the first rendering, you render the scene
to see how the shadows appear without using caustics.
To
set Render options for raytracing
- In
the Render Settings window, select
the Quality tab and set the Quality Presets setting
to Production.
The Production preset
ensures that the refraction level settings (found in Raytracing
Quality section) are at a level high enough to render
objects with translucency (for example, the bottle). The Production preset
also sets the anti-aliasing level for the image.
- Close
the Render Settings Window.
Rendering the image
When you render an image, all of the objects,
lighting, shading materials, and image quality settings are used
to calculate the image, from the camera’s view.
To
render an image using mental ray for Maya
- Click
in the perspective window to indicate which view you want to render.
- In
the Render View window, click the Render
Current Frame icon.
The bottle scene renders using the mental ray
for Maya renderer and the image appears in the Render View window.
.
TipIf the rendered image appears either too
small or too large in the Render View window,
select View > Frame Image from
the Render View menu to fit the
image to the Render View.
- Once
the render is complete, click the Keep Image icon
in the Render View window.
Keeping the image allows you to compare it to
any subsequent test renders. In this lesson you compare each successive
rendered image to the previous one to observe how the changes you
make to render settings affect the rendered image.
The rendered image shows the following:
- A translucent
bottle with apples beside it casting shadows towards the rear of
the scene. Notice how the shadows appear when raytrace rendered.
- The
distortion of the table surface in the translucent glass effect
based on the refractions and reflections.
- A dark
region on the surface of the bottle. This results from the bottle reflecting
the empty black area of the scene in front of it.
In the next section, you turn on the caustics
rendering attributes and render the scene.