LuxCoreRender Forums

Sharlybg wrote: ↑Mon Oct 15, 2018 9:30 am I mean your final Goal. wich kind of render output you want to achieve.

V-Ray_photo reference_3D render.jpg

I don't know why does it matter, atm the project is undergoing some fundamental change.
But let's say this picture in the attachment represents the scene. And dlcs would take forever even with archglass, so I dropped the idea for now.

lacilaci wrote: ↑Mon Oct 15, 2018 9:55 am I don't know why does it matter, atm the project is undergoing some fundamental change.
But let's say this picture in the attachment represents the scene. And dlcs would take forever even with archglass, so I dropped the idea for now.

You should use a point light source (may be with and IES profile) or a emitting box for each bulb, trying to render each bulb with thousands of triangles is out of scale.
Or at least, you should have different LOD (Level Of Details) for bulbs to use according the distance from the camera.

Dade wrote: ↑Mon Oct 15, 2018 10:03 am

lacilaci wrote: ↑Mon Oct 15, 2018 9:55 am I don't know why does it matter, atm the project is undergoing some fundamental change.
But let's say this picture in the attachment represents the scene. And dlcs would take forever even with archglass, so I dropped the idea for now.

You should use a point light source (may be with and IES profile) or a emitting box for each bulb, trying to render each bulb with thousands of triangles is out of scale.
Or at least, you should have different LOD (Level Of Details) for bulbs to use according the distance from the camera.

emitting box is the method I would really want to use...
However, hiding the box from camera doesn't hide it in reflections and that box still occludes other lights and reflections, so not only will the lightbulb glass look wrong but I will see that emitting box in all reflections, see attachment.

just use simple plane mesh with opacity texture to reproduce the shape of your bulb filament : easy and efficient

Sharlybg wrote: ↑Mon Oct 15, 2018 11:43 am just use simple plane mesh with opacity texture to reproduce the shape of your bulb filament : easy and efficient

This is indeed one of the most usefull cases for opacity. A completely invisible but light emitting object.

A filament plane modelled with reduced resolution bezier curves can limit number of lights.

I‘ve observed number of lights around a few 1000 has low influence on render time (Room with Gym Balls), but this was without DLC).

FarbigeWelt wrote: ↑Tue Oct 16, 2018 10:22 am

Sharlybg wrote: ↑Mon Oct 15, 2018 11:43 am just use simple plane mesh with opacity texture to reproduce the shape of your bulb filament : easy and efficient

This is indeed one of the most usefull cases for opacity. A completely invisible but light emitting object.

A filament plane modelled with reduced resolution bezier curves can limit number of lights.

I‘ve observed number of lights around a few 1000 has low influence on render time (Room with Gym Balls), but this was without DLC).

No, this has to work without that ridiculous workaround, not efficient at all... Simple box emitor is as far as I'm willing to go, it's what you do in any other renderer..

lacilaci wrote: ↑Tue Oct 16, 2018 10:29 am [

No, this has to work without that ridiculous workaround, not efficient at all... Simple box emitor is as far as I'm willing to go, it's what you do in any other renderer..

A nore efficient way might be to copy filiament and reduce complexity with one of the mesh tools. At same place with correct materials high poly keeps visible and low poly delivers light.

FarbigeWelt wrote: ↑Tue Oct 16, 2018 1:12 pm

lacilaci wrote: ↑Tue Oct 16, 2018 10:29 am [

No, this has to work without that ridiculous workaround, not efficient at all... Simple box emitor is as far as I'm willing to go, it's what you do in any other renderer..

A nore efficient way might be to copy filiament and reduce complexity with one of the mesh tools. At same place with correct materials high poly keeps visible and low poly delivers light.

You cannot keep things at the same place if luxcore can only hide camera rays, and cannot hide diffuse contribution of the hi-poly... There are workarounds sure, but no way that's an efficient workflow. There is no easy way around this,

we need
1.the ability to disable light occlusion from other lights - so that an invisible light doesn't cast it's own shadow (the fact that light cannot disable it's own shadows makes invisible lights near impossible to use within interior)
2.disable diffuse contribution so that emissive light sources can glow and be seen in reflection but don't contribute to lighting.
3.disable shadow casting so that we can optimize scenes with refractive glass and curtains and whatnot.(This should also apply to DLCS so that it can pass through translucent and refractive materials effortlessly, and same goes for potential secondary gi caching)
4.disable visibility in reflections so that invisible lightsources and other objects can be hidden from being reflected.

You have to understand that it's no point if I can have hundreds of lights if I cannot use one object as visible light and simplified mesh as actual lightsource.

Next step is exclusive/inclusive lighting per object for a complete control over lighting, that one even cycles don't have, but it is planned for 2.8 at some point.

Actually I thought well contribution of diffuse light is one main aspect to use luxcorerender.

FarbigeWelt wrote: ↑Tue Oct 16, 2018 1:38 pm Actually I thought well contribution of diffuse light is one main aspect to use luxcorerender.

How does this change? What I'm asking for is basic feature of any archviz renderer, it is there to allow for in-camera compositing, so that you don't have to render separate layers and masks and spend your life in compositing all that together. This way you can render single frame, save from framebuffer and you're 99% done in some cases.

This doesn't cripple the renderer, even "the ground truth render engine" has this feature since forever I guess: https://support.nextlimit.com/display/m ... visibility

and can even exclude emitters/lights: https://support.nextlimit.com/display/m ... e+emitters