As cool as resin-based 3D printers are, they’re not without their shortcomings. One sore point, especially for those looking to document their prints, is that the translucent resins often favored for stereolithography can make the finest details difficult to see. Injecting paint into the model is how [Andrew Sink] decided to attack this problem, and the results are pretty striking.
For sure, this isn’t a problem that everyone making resin prints is going to face. Some resins are nicely opaque, and the fine details of a print show up just fine. But transparent resins lend a nice look to some projects, and might benefit from [Andrew]’s technique. It’s pretty much as simple as it sounds: choose a hollow model — or modify an existing one — print it up in the usual way, and clean thoroughly inside and out with isopropanol before curing under UV. Using a curing station that can get UV light up into the voids is probably a smart idea.
To finish off, the cured model is injected with acrylic paint. Nothing special here, just craft store acrylic in a syringe. [Andrew] seemed to prefer a thicker paint; we don’t want to second guess, but intuitively a thinner paint would seem to have some advantages. In any case, be sure to provide adequate vent holes for the displaced air. The video below has a few before and after shots, and the technique really works well to show off surface detail. Plus it just plain looks cool.
This seems like a good technique to keep in mind, and might even work well for hollow FDM prints done with transparent filaments. Still on the fence about FDM vs. SLA? We can help with that.
Stereoscopic vision works by having the brain fuse together what both eyes see, and this process is called binocular fusion. The small differences between what each eye sees mostly conveys a sense of depth to us, but DiCE uses some of the quirks of binocular fusion to trick the brain into perceiving enhanced contrast in the visuals. This perceived higher contrast in turn leads to a stronger sense of depth and overall image quality.
To pull off this trick, DiCE displays a different contrast level to both eyes in a way designed to encourage the brain to fuse them together in a positive way. In short, using a separate and different dynamic contrast range for each eye yields an overall greater perceived contrast range in the fused image. That’s simple in theory, but in practice there were a number of problems to solve. Chief among them was the fact that if the difference between what each eyes sees is too great, the result is discomfort due to binocular rivalry. The hard scientific work behind DiCE came from experimentally determining sweet spots, and pre-computing filters independent of viewer and content so that it could be applied in real-time for a consistent result.
Things like this are reminders that we experience the world only through the filter of our senses, and our perception of reality has quirks that can be demonstrated by things like this project and other “sensory fusion” edge cases like the Thermal Grill Illusion, which we saw used as the basis for a replica of the Pain Box from Dune.