Environment compositing node

Applies an environment map to an image.

All Parameters Local variables Example files

See also: Bump, Lighting

Environment applies an environment map to an image which contains either a normal or bump map. Both cubic and spherical maps are supported (cubic maps layouts for Renderman and Mental Ray are supported).

The environment map can be rotated around the scene, and it can be blended with the input image.

See how to create an environment/reflection map.

Tip

To only show the environment map on 'shiny' parts of the image, mask out the shiny parts and connect the matte to the Mask input.

Tip

To make the environment map blurrier, use a blur or defocus COP on the environment map.

Note

Normal maps generally produce better results than bump maps.

Overloading VEX Parameters

This operator is implemented in VEX, which supports parameter overloading. If the first input has a plane which matches an operation parameter’s channel name, the input plane will be used as the parameter’s value, effectively overriding it. The overloaded parameter is then evaluated from the plane on a per-pixel basis.

eg. If the input COP has the following planes:

C{r,g,b}
A
fogdens
and it is fed into a VEX Fog COP, the fog density will be determined at each pixel by the fogdens plane, since the Fog Density parameter’s channel name matches the 'fogdens' channel name.

Scoping

This operation may be restricted to certain planes, or components of planes. In addition, the operation may be applied to a subset of frames within the sequence. An image must have both its frame and plane scoped to be modified.

Images that are not modified are passed through, which does not take any memory or processing time.

Masking

This operation may be masked, which restricts the operation to an area of the image. The mask may be inverted, brightened or dimmed.

The mask input is on the side of the node. The label on the connector indicates the plane being used as a mask.

The mask input can also be scaled to fit the output image’s resolution, if they differ. However, if this node changes more often than the mask input, it is faster to place a Scale COP in front of the mask input to do the resize, as the resize will not occur on every cook of this node.

Parameters

Environment

Map Rotation

Rotates the map about the scene.

Environment Map

Selects the type of map connected to input 2.

Spherical

The map is a spherical project onto a rectangular image (much like a world map).

Cube (Cross - RenderMan)

The map looks like a sideways cross: Left Front Right Back, with Top above Front and Bottom below.

Cube (Strip - Mental Ray)

The map is a horizontal strip of images, each in various orientations. The order of images is Right, Left, Back, Front, Bottom, Top.

Cube Face X Size

For cubic maps, this is the width of one face.

Cube Face Y Size

For cubic maps, this is the height of one face (normally the same as the width).

Reflect Amount

The amount of the environment map to blend in.

Ambient Amount

The level of the input image, from 0 (black) to 1 (same image).

Direction Source

Environment mapping can be done from either a normal map (usually generated by a Renderer) or a bump map (can be generated with the Bump COP). Normal maps generally produce better results.

Normal Map

Use a normal map ('N').

Bump Map

Use a bump map ('B').

Mask

A mask can be chosen to limit the effect of the operator to areas defined by the mask. The mask can be taken from the mask input (side input) or from the first input itself.

Effect Amount

If no mask is present, this blends the output with the input by a constant amount (0 = all input, 1 = all output).

If a mask is present, this amount multiplies the mask.

Operation Mask

Selects the mask plane to use as a mask from the mask input. The mask can be selected from:

A mask can be a component of a plane or an entire plane. If a vector plane is supplied as a mask, its components are multiplied by the images' components.

Scalar Mask ('A', 'C.r')

C.r = I.r * M
C.g = I.g * M
C.b = I.b * M
Vector Mask ('C')

C.r = I.r * M.r
C.g = I.g * M.g
C.b = I.b * M.b

First Input

Useful for masking the operation to the image’s own alpha plane.

Mask Input

Selects the mask from the side mask input.

Off

Turns off masking, without requiring disconnection of the mask input (useful for temporarily disabling the mask).

Resize Mask to Fit Image

If the mask image is a different resolution than the output image, turning on this parameter will scale the mask to the output image’s resolution.

If this node is changing constantly, and the mask is not, it is somewhat faster to put a Scale COP down to do the resize for the mask image. Otherwise, the scale will occur every time this node cooks.

Invert Mask

Inverts the mask so that all fully 'masked' portions become unmasked. This saves you from inserting an Invert COP after the node with the mask.

Scope

Plane Scope

Specifies the scope for both the RGB components of Color, Alpha, and other planes. The (C)RGBA mask only affects Color components and Alpha. 'C' will toggle all the RGB components.

For planes other than Color and Alpha, the plane name (plus component, if applicable) should be specified in the string field. The pulldown menu can be used to select planes or components present in this node.

A plane is specified by its name. A component is specified by both its plane and component name. The '*' wildcard may be used to scope all extra planes. Any number of planes or components can be specified, separated by spaces.

Examples:

P
N.x N.y
P N Pz

Frame Scope

Frame Scope

Allows scoping of specific frames in the frame range. This is in addition to the plane scope (so a plane at a certain frame must be both plane scoped and frame scoped to be modified).

All Frames

All frames are scoped.

Inside Range

All frames inside a subrange are scoped.

Outside Range

All frames outside a subrange are scoped.

Even Frames

Even numbered frames are scoped.

Odd Frames

Odd numbered frames are scoped.

Specific Frames

A user-defined list of frames are scoped.

Frame Range

For Inside/Outside range, this parameter specifies the subrange of the sequence to scope (or unscope). This can be edited in Timeline viewer mode ( Ctrl + 2 in viewer).

Frame Dropoff

For Inside/Outside Range, this parameter specifies certain number of frames before and after to slowly ramp up to scoped. The operation will be blended with its input to 'ease in' or 'ease out' the scoping effect over a number of frames. This can be edited in Timeline viewer mode ( Ctrl + 2 in viewer).

Non-scoped Effect

For unscoped frames, this sets the blend factor between the input and modified images. Normally this is zero (use the input image). By setting this to a non-zero value, you can make unscoped frames be 'slightly' unscoped. The value can vary between 0 (unscoped) and 1 (scoped).

Frame List

The frame list for 'Specific Frames'. Frame numbers should be separated by spaces.

Automatically Adjust for Length Changes

If the sequence range changes, enabling this parameter will adjust the subrange and frame dropoff lengths to fit the new range.

Local variables

L: S: E: IL: SR: NP: W: H: I: IT: AI: PI: PC: CXRES: CYRES: CPIXA: CBP: CWP: CDEPTH:

Example files

EnvironmentMap

$HFS/houdini/help/examples/nodes/cop2/env/EnvironmentMap.cmd

Load | Launch

This example demonstrates how the Environment COP is can be used to simulate multiple light sources around a scene. This is a good method of changing scene lighting, because 2D images will render faster then 3D.

Usages in other examples

Example name Example for