| dev369 (dev369) | |
| Aug 27 2020, 10:48 PM |
| Aaron Carlisle (Blendify) |
| Clément Foucault (fclem) |
| dev369 (dev369) |
| Evan Wilson (EAW) |
| Germano Cavalcante (mano-wii) |
| RedMser (RedMser) |
System Information
Operating system: windows 10
Graphics card: rtx 2070 super
Blender Version
Broken: 2.8.5
Worked: (newest version of Blender that worked as expected)
screen space reflections are not applied to an object from environment that has been held out using holdout button on collection. since the stuff is still there when holdout is applied to background, screen space should still be applied to objects that are not held out.
here is an example:
It is quite possible that this is a limitation.
Especially because, as the name says, "Screen Space Reflection" simulates reflection with what is being drawn on the screen space.
If nothing is being drawn in the screen space, there is nothing to display as a reflection.
But I'm not sure if holdout works as an overlay.
@Clément Foucault (fclem), can you confirm?
is it really impossible to get the holdout effect with screenspace applied? i dont believe so, you just dont want to do it because it says "screen" in there. but in reality it would be very useful to have screen space applied. in EEVEE as it currently stands, holdout is useful only to render out masks and that is about it. without screen space effects it is useless for any even remotely realistic renders. so its pretty useless. such a disappointment.
Another option is to use ID Masks.
https://docs.blender.org/manual/en/latest/compositing/types/converter/id_mask.html
there is no object or material id pass in eevee. to get this effect you have to render a separate view layer with holdout applied for the mask, then use this mask to filter out the original render to single out object. that is twice the amount of work and twice the rendering. if screen space worked with holdout you could just holdout the background and easy no need even for compositing.
also, holdout implies to just "hold out" the object that is being held out while preserving all the indirect effects. you can argue that screen space is just screen space, which it is. but it is used to apply an indirect effect on an object, just using screen space to calculate the effect. what stops you from calculating this screen space effect and apply it to the object while preserving the holdout? it is really counter intuitive incomplete and useless and worse i am guessing people dont understand that screen space is not being applied because it is not always obvious, someone can do a ton of work and then realize that stuff doesn't look the way it should. at least update the wiki to make this obvious if nothing else
It is a known technical limitation. Eevee uses it's own render buffer as source of light for indirect illumination which is why this does not work.
The issue is not so simple as material can be half holdout and blended so you need a system that would handle all of this.
Maybe @Evan Wilson (EAW) can add this exception to the manual.