SteveW wrote:Got it working....thanks! Both suggestions were good. I got the 3D Transform working.
Great.
SteveW wrote:I also saw that you don't have to have every node go to the same Merge3D. You can daisy chain them to make a much neater layout.
Yes.
Many users often make a central "hub" by connecting everything to a single Merge 3D node. I also see people doing this with MultiMerge in 2D.
I think merge nodes with many connections are useful for grouping similar, already-positioned elements. However, they can restrict the user's compositing process.
It's easier to see and work with a segmented flow where each element that will be manipulated is merged separately. Merge and Transform nodes build upon each other (concatenate), so they don't cancel each other out.
Segmenting elements makes the work and overview easier.
When working in 3D space, I often use one Merge 3D node for the geometry, and then two other Merge 3D nodes: one for the lights and one for the camera.
If it's a more complex scene with multiple render passes, I'll put the lights and camera in a single Merge node. This makes it easy to link them for the other passes.
For example, if I want something to orbit around something else (like in your scene), and I want the orbiting object to be a glowing ball, here's how I might approach it.
Since there isn't a built-in glow option for 3D, it has to be done in 2D. If the glowing ball is always in front of everything else, you can add a glow effect to the texture before plugging it into the 3D shape.
However, if the glowing ball needs to appear in front of objects sometimes and behind them at other times, you can use multiple passes to create holdout masks. Then, after rendering, you can add the glow only to the 3D pass that renders the ball with the holdout mask.
In that case, it's helpful to have the camera and lights in one Merge node, which can be easily shared among different render passes. The ball and the figure would be merged separately, each in its own Merge node.
This setup would be virtually impossible to achieve using a single Merge 3D node.
Essentially, you render out different render passes using the same lights and camera (hence, one Merge node that's easy to share). You have two separate passes: one for the background and one for the ball. But you don't just render them; you also render them with a holdout mask. You can achieve this by using an Override 3D tool to create the matte.
It would look something like this.
- sshot-181.jpg (69.95 KiB) Viewed 247 times
- sshot-182.jpg (69.14 KiB) Viewed 247 times
- sshot-183.jpg (50.52 KiB) Viewed 247 times
Using multiple render passes and merge nodes can also be helpful for managing elements built outside of the main composition, making them easier to handle. For instance, if you're adding particles to a 3D scene, you can create them separately and then add them using a dedicated Merge 3D node.
Another benefit is the ability to reuse elements throughout the scene. By placing lights, cameras, and other elements further down the node graph, you can use the same setup but branch out from earlier nodes. This is particularly useful when combining elements multiple times.
Wed May 07, 2025 1:54 pm