Emission material emitting light and shadows in Eevee as in Cycles?
Hello,
I don't know if what I intend to suggest is possible... and if it is, if it is supposed to be added soon... But even if it's less realistic than in Cycles, using often in 2.79 this material and very interested in Eevee, I'd like to know if it would be possible to make the material "Emission" acting like a light... like Cycles is able to do...
Even if it has to make a longer render time and / or to use a part of Cycles render engine to proceed so, I'd really love to use Eevee, the emission material, and to see the light and the shadows emitted by the object with that material.
PS: I forgot to deactivate the HDRI in Cycles, but we can see the shadows and lighting emitted by the sphere however...
16 Comments
I was wondering if we could use multiple render engines for one scene and combine the result. Say if the background scene is rendered in Eevee and the object with the emission material can be rendered in Cycles. Since they are inter -compatible it can be possible.
* @Hanna Calra * I thought the same way too.
Though, actually, to get this result, this will ask an additional work in compositing and to render the scene twice: once with Eevee, once with Cycles.
Or we could ask for Blender to add a feature to render such objects with Eevee and such objects with Cycles and to automate the render like this but... even if I don't really know how render engines really work, I'm quite convinced it should be a hard thing to ask... especially if this is a feature asked just for one material in particular...
Probably not worth asking, even if I'd be really happy to find this new feature.
OK I did this youtu.be/Ni15L_uCkEw
* @zgorg2004 * Thank's, zgorg2004 Though, this is not really what I'm searching. Your technic is for sure very good to simulate an emission from a Sphere... Though, what I needed was to be able to emit light with some more complex objects... Like... if you want to make a shining ring, or something even more complex, a point light could be not enough... Well, you could probably cheat with other lighting / special effect or else, I guess... maybe with more lights, but I think the faking technic you're showing in this video won't be enough.
This is why I wanted to ask if it was possible to really make this shining emission shader on Eevee working as in Cycles.
In the end, my subject was not about making a sphere emitting a light, but about allowing any object with any shape to emit a light.
* @Ak MC * well I see what you mean with more complex objects. the light should come from the object directly. now I think what I did is shit. ahaha and I should know it unconsciously because doing this video took me hours. I recorded it again and again still having some problems. today I did one in ten minutes
No, It wont be possible anytime unless:
* @Pawel Piotrowski * I know about baking, but ideally, this is not what I'm looking for. I'd like to be able to see the result without having to bake.
So... it would be more Realtime I'm asking for if possible, yeah.
Though, I know the project "Eevee render engine is still very young" and I'm already very amazed by how Blender developpers managed to make it so great already.
So I can wait until it's possible for them to add this feature as in Cycles, but I was keen on asking it there to let us know I (and the people who liked this post) are very interested to get this feature once it is possible.
Even in Cycles, the emission seems way off, say for headlights from a car, or a concert stage light, requiring huge wattage still with weak scene influence. Perhaps, they require insane sample counts, but adaptive sampling does not seem to catch them either. An automatic and adaptive light/portal creation by the renderer may be an answer. I am also not convinced things are as "Physically Correct" or whatever as often touted with with every new fad algorithm copied around, only to be proven false decades later.
this is possible to fake it I will show you in a video. Incoming but with improvement could be automated...
You have to add a lightprobe>irradiance volume and bake it. It does the job. Crank up the probe resolution for better quality {attachment Screen_Shot_2019-06-29_at_191634png}
* @g3ntile * Irradiance volume?
Mmmh... I didn't know about it. Will search some tutorials to understand it better... Though, this doesn't seem to be what I'm asking for. Especially that I'd prefere the Emission material to work directly once we use the "Rendered shading" on 3D view, so baking would not be necessary.
Thank's for the information about Irradiance volume though. This may help me until they improved the material, if the developpers can do this one day. ^^
* @g3ntile * Well, I just saw how Irradiance volume and baking indirect lighting is working, and no, this is not at all a good alternative to the Emission material in Cycles.
It emits light, indeed, but no shadows. It's used to enlighten faces better with light bounces... it is a good replacement of another feature available with the old Blender internal render engine (I don't remember the name), where there also was a kind of Emission material... or emission option on the object directly, but there was the same problem: No shadows made by the object emitting light.
For the moment, only Cycles render engine allows it.
* @Ak MC * The problem here is that you're asking for a raytracing feature (polygons that emit light) and eevee is not a raytracing engine. And without rays you have to bake GI. EEVEE is designed to be a –sort of– realtime engine, so they ruled out raytracing in favor of speed. Realtime raytracing is a technology in its infancy, at least for the vast majority of people. Currently only the RTX cards support that, and very few implementations take advantage of that feature. Converting EEVEE into a raytracing engine requires a full rewrite from scratch, so I don't think that will be possible.
* @g3ntile * Ah! I see...
Well, I don't know a lot about how a render engine work in term of codes, etc..., but I was afraid to get an answer like that though, indeed.
If you're right, then, I guess I should keep using Cycles for the Emission material or find another way to give the feeling the object with this material is a light source... probably by cheating with point lights, I guess...
Thank's for the precision.
it has to evolve, it will be possible I think doing an hybrid through parameter such in ligh path node. and bake could be done automatically when activated (even temporarly) using maybe bounding box on a selection of several objects...
* @zgorg2004 *
That sounds a lot like a lightprobe to me. Try it. It's not perfect, but gets somewhat close. Eevee is not a raytrace engine, so words like "path" or "ray" make no sense at all in eevee's world. Even the shadows are faked (shadowmaps).
If you really need raytracing features you should use a raytracing engine.