I’m starting to familiarize myself with 2.8 in preparation for the Beta, but there’s very little info about it out there. So I’m left with a lot of misc questions, especially about EEVEE. Any help appreciated!
EEVEE seems to have very limited passes compared to Cycles. Do we know if there’s going to be any more passes, such as color or shading or other equivalents of Cycles passes?
One thing I’d really like to use EEVEE for is quickly rendering effects, such as bloom and volumetrics, and compositing them over Cycles. However there seems to be limitations. I can’t see any way to separate Bloom out. The best I can do is use a shader that’s just black and white gloss with bloom, and then color ramp it in the compositor. Anyone know better tricks or if this will get more options?
Do we know how exactly the Screen Space Reflections work? I have found tutorials of people showing them and the different options, but I’m looking for more in depth info. I get that they are faking indirect light somehow, but how, and what’s the limitations?
If you are using Bloom and part of the glow overlaps the background, and the world is set to transparent, you don’t get the bloom in the final render. Any way around this?
Hey, here is an attempt to answer your questions :
1/ Yes there will be more passes but after 2.80 release.
2/ What about using the Glare node instead of Eevee Bloom ? And at least , this effect is quite easy to reproduce with some nodes, and I think it’s too much work to render a 2nd Eevee scene just to add bloom.
For volumetrics indeed you have to set a Eevee scene with black materials for now.
3/ SSR is faking real raytraced reflections not Indirect Lighting. When Eevee renders, internally it produces many passes. By using Z-pass , Normal-pass, Color-pass and Camera data, it can get accurate position of pixels in the 3D space. Then it raytrace reflections using these informations. It’s faster than cycles’s raytracing who go over every objects and polygons.
The main limitation is that it will reflect only visible stuff on the screen. So an object A won’t be reflected on an object B unless object A is in the render. As you guess, occluded parts from object A aren’t reflected either.
So it’s better to use SSR to add some blurry reflections, to ground objects more, but you can have really clean and sharp reflections as you would do with a true raytracer.
4/ see point 2, if you’re doing compositing, it may be better to add glow/bloom effect at that stage.
I though I would use comp glare to save my day on my current quick project, but I can’t. Both bloom and comp glare works on the whole image, whereas I need material pass to control what actually gets to glare.
Yes, there are more time consuming ways to do it, like rendering out in separate object passes, but I really can’t afford it - the guy who needs it actually comes asking for it while I’m typing this, so…
Looking forward to material id and object id passes.
Hum, you can use ID mask to tel what objects need to respond to glare, or , if your materials are setup to be emissive or smooth enough to get strong highlights, then you can just apply the glare node to the whole image and it should add a glow where it’s needed and natural. Just like with the bloom effect from eevee !
Needed, yes. Natural, no. I wanted the image of a projector lens to glow because of its high intensity at that size. In real life, this intensity is directional, but for renders I just attach an image to the lens and make it emissive - which makes it spread light in all directions. But I had other stuff in the room with sharp bright highlights where we need to do some photoshop work on, and I can’t have a glow in those areas. If I had cryptomatte or object or material ID on the lens, I could easily isolate that. I ended up rotating other equipment so they didn’t catch a highlight, but not ideal solution. Yes, there are ways around it, I’d just prefer if I could do something simple that I could afford timewise.
Even the stray light outside the actual image pyramid is very bright. Image is shot from a VC camera just outside this (not modelled) light pyramid.
If you want to only make the projector image glow, you can use the Emission pass and apply glare to only that (Make sure Mix factor is 1, so that you don’t double the original emissive intensity), and just add that on top of the rest of the image.
All directly Emissive objects will glare, but only they will contribute to the bloom.
I don’t have Emission pass available in Eevee. I could add manual mask for the lens and glare that, but I had several camera angles I needed to do. I considered going back and forth with Cycles and a low sample obj/mat ID pass, but there wasn’t enough time.
They were happier with the results than I was though
You can turn off antilaliasing by rendering only one sample IIRC , that is the best behavior when working with colored ID. But yes you can render twice the size and scale down the image after making the color key to get proper antialiased IDs.
I haven’t looked at how to handle that in blender but should be possible. At the time I was looking at it , it was complicated to have one renderlayer with eevee/cycles and one with workbench . This setup works better if you export renderpasses to composite them latter.
Also I’ve found that it’s possible to export Screenspace Normal pass using workbench in matcap mode with the normal matcap.
Later you’ll need to do a srgb->linear conversion and remap the color beetween -1 and 1 to get a normal pass that you can use to do some relighting.
All in all , I founded that workbench engine is also an awesome render addition to blender next to eevee.
