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Underwater lighting - parti_volume
Underwater lighting - parti_volume
callum ridley, updated 2010-07-18 01:12:33 UTC 199,061 views  Rating:
(9 ratings)
Page 4 of 4

Part 4 - The "parti_volume" Node

In this section we will be looking at how to set up the "parti_volume" node which over time has become a complicated node to setup. It is this node that makes this tutorial work. although there are differet ways of using the "parti_volume" i have found this setup to be the most dynamic with the use of photonic lights rather than Mental Rays' "Physical Lights"

Setting up the photonBoundry

1. select the photonBoundry Cube and right click and select "Assign New Material". Select "Transmat" from the Mental Ray nodes section.

2. Open up the Shading Group Attrributes by clicking on the "Go to Output Connections" button output_connectionsand open up the "Mental Ray" section.

3. Scroll down to the "Custom Shaders" section and click the chequered box next to the "Volume Shader" attribute. load into there the "parti_volume" found under the "volumetric Materials" section under the Mental Ray nodes. leave the settings for the "parti_volume" alone for now.

Setting up the waterSurface

4. Select the waterSurface plane and open up the attribute editor for it.

5. Select the "dielectric_material1" tab and click the "Go to Output Connections" button output_connections.

6. Scroll down to the "Custom Shaders" section and where it says "Volume Shader" type: parti_volume1

7. Now where it says "Phot Volume Shader" click the chequered box and select "parti_volume_photon" from the "Photonic Volumetric Materials" section under the Mental Ray nodes. Again leave the settings alone for the node as we'll set them up later.

Setting up the Camera

1. open up the attributes for the camera by clicking on the "camera Attributes" button in the viewport (it's the second button in on the "mini shelf" in the perspective viewport.) See figure 4.1

minishelf
figure 4.1

2. Scroll down and open up the "Mental Ray" section.

3. In the "Volume Shader" box type: parti_volume1

Almost done now!

Setting up the parti_volume nodes

1. open up the hyper shade and select the "parti_volume1" material that you created earlier and use the following settings. See figure 4.2

parti_volume
figure 4.2

2. Back in the Hypershade open up the "Utilities" tab and open the attributes for the "parti_volume_photon1" node you created earlier. Use the following settings. See figure 4.3

parti_volume_phot
figure 4.3

Quick note: a few people struggled with the tutorial and it would seem the problems are witht he parti_volume and parti_volume_photon setup. when setting the scatter attribute make sure it is a dark grey and not a black colour.

The end result

final_image

if you want to change the colour of the light coming in then all you need to do is change the "Col" and "Outside Color" of the "dielectric_material1" shader to the colour of your choice. example below.

colour_image

Well thats its guys. I hope this tutorial has been of help. It's my first attempt at a tutorial so your feedback would be much appreciated!

Written By
Callum Ridley