Compositing Terragen Render Elements

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Compositing with Terragen's render elements allows you to recreate and fine-tune the final rendered image or "beauty pass". The compositing project should be set up in linear colour space and you will use an "Additive" workflow approach, which means setting the render element's merge or blending mode to the equivealent of "additive" in your 2d software package. In the Nuke software, this means setting the merge node to "Plus", while in the Fusion software, this means setting the merge node's "Apply Mode" to "Normal", "Operator" to "Over", and "Alpha Gain" to "0.0".

tgRgb[edit]

The simplest example of combining render elements to match the Terragen beauty pass, which is sufficient for many projects, is this:

tgRgb = tgSurfRgb + tgAtmoRgb + tgCloudRgb

tgRgb = tgSurfRgb + tgAtmoRgb + tgCloudRgb

Note that each of these render elements are blended or merged together in an "additive" way, and that the end result matches the Terragen beauty pass.

tgSurfRgb[edit]

Sometimes you'll want to adjust or fine-tune your image, so each of the three "Rgb" render elements above can be recreated by combining other render elements. The newly combined elements then replace the "Rgb" render element in the comp.

There are two methods for recreating the "tgSurfRgb" element. The first gives you control over direct and indirect lighting. The second gives you control over the diffuse and specular as well.

For control over direct and indirect lighting on a surface use:

tgSurfRgb = tgSurfDirect + tgSurfIndirect.

tgSurfRgb = tgSurfDirect + tgSurfIndirect


For control over the diffuse and specular lighting on a surface choose this:

tgSurfRgb = tgSurfDirectDiff + tgSurfDirectSpec + tgSurfIndirectDiff + tgSurfIndirectSpec.

tgSurfRgb = tgSurfDirectDiff + tgSurfDirectSpec + tgSurfIndirectDiff + tgSurfIndirectSpec

As you can see, using either of these methods results in matching the Terragen beauty pass, and adds the ability to "dial in" the amount of surface lighting you want.

tgAtmoRgb[edit]

Likewise the atmosphere "tgAtmoRgb" render element can also be recreated by combining the tgAtmoDirect and tgAtmoIndirect render elements, which will give you control over the atmosphere's direct and indirect lighting.

tgAtmoRgb = tgAtmoDirect + tgAtmoIndirect

tgAtmoRgb = tgAtmoDirect + tgAtmoIndirect


tgCloudRgb[edit]

And finally, the clouds "tgCloudRgb" render element can be recreated in a similar fashion, by combining the "tgCloudDirect" and "tgCloudIndirect" render elements.

tgCloudRgb = tgCloudDirect + tgCloudIndirect

tgCloudRgb = tgCloudDirect + tgCloudIndirect


Results of additive workflow[edit]

In the image below we can see the compositing node layout and the results of the “additive” workflow.

Composite using render elements.

A single object or device in the node network which generates or modifies data and may accept input data or create output data or both, depending on its function. Nodes usually have their own settings which control the data they create or how they modify data passing through them. Nodes are connected together in a network to perform work in a network-based user interface. In Terragen 2 nodes are connected together to describe a scene.