Step-by-step: Discover how to give a creature a convincing internal glow
1I want to maintain a humanoid base anatomy that will occlude the light on the creature’s insides. To begin, I take some photos of a life-size skeleton model and use it to draw out the placement for the internal anatomy on top of my sketch.
2I plot out a Multiply layer with a dark fill of the bones in front of a core light. I set the Opacity to 35 per cent and use a layer mask to erase out areas the opaque body forms will cover, and soften the edges on the bones that would recede back in space.
3While most of the lighting effect is created with rendering of the spaces that are more transparent, I also use an Overlay layer to create a stronger glow effect in areas that are closer to the light source, and spaces that have thinner flesh.