A_P_TPC_Vol11_2015_

3D AND PHOTOSHOP

001 Place the Normals pass

Place it as the top layer in the 3D group. We will make masks with it, so it is better

to sit at the top so it is easy to access throughout the rest of the process

003 Adjust the Channel Mixer

Set the Channel Mixer on Monochromatic and reduce the Red value to the minimum,

and then raise the Green value to the maximum setting

002 Add Adjustment Layers

Link a Hue/Saturation adjustment layer to the Normals pass, and also add and

link a Channel Mixer adjustment layer above it

12

PUT THE MASK TO GOOD USE

Go to the Channels tab, and click while you

hold Cmd/Ctrl pressed on the RGB Channel to select

the white parts of the image. Go back to the layers,

deactivate the Normals layer, and add a Curves

adjustment layer while you still have the selection

active. Pull the curve up to the maximum, and you

can see how the object gets brightened just as it

was intended. The image looks overexposed in

some areas, and also some regions might be better

off without the Curves adjustment. Therefore, group

the Curves adjustment layer and add a layer mask

to the group. Invert the mask and paint with the

brush only where you want the adjustment to affect

the image.

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OBTAIN THE DESIRED MASK

The image needs more light coming from

above, and instead of going back to the 3D scene,

making tests, rendering again and losing several

hours, you can use this technique, and have an

undestructive and controllable tool at your disposal.

In order to obtain the desired mask, play with the

Hue/Saturation options – the values that work best

are +30 for Hue, +100 for Saturation and -30 for

Lightness. You can see how the surfaces that face

up are all covered in white, while the rest of the

image is black, which means we can use this result

to illuminate from above.

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REPEAT THE PROCESS

You can always reactivate the Normals

layer and tweak the Hue/Saturation settings until

you get other useful masks. You can direct your

curves to affect surfaces from every side you wish,

and you can also darken areas, not only brighten

them. Always group your adjustment layer, and add

a layer mask to the group to paint over it, so that

you can have maximum control over your work.

10

CREATE MASKS WITH THE

NORMALS PASS

The Channel Mixer already offers a greyscale mask,

but in order to have full control of this technique, you

have to use the Hue/Saturation adjustment layer. As

you move the Hue slider, the image changes, just

like if there is a light source that moves around the

object. Also, both the Saturation and the Lightness

sliders can be used in order to play with the contrast

of the mask. This technique is extremely efficient,

because you can rapidly create masks to act from

whichever direction upon the rendered object.

09

USE THE NORMALS PASS

This render element is a 2D representation of the 3D objects, based on the normal angle of

the camera. The image is made up of tones of red, blue and green, which represent the axes of the

tri-dimensional space (x,y and z). Although often ignored, it can be used to easily create masks, being

based on RGB values.

EASILY CREATE ILLUMINATION MASKS

BRIGHTEN AND DARKEN PARTS OF YOUR IMAGE BY USING THE NORMALS PASS

001

Always group your

adjustment layer and

add a layer mask to the group

to paint over it, so that you

can have maximum control

over your work

002

003