It is possible to render like a technical drawing?

[Vasjly]

Hi all!
I want to generate variations of a scene by some python scripts I made to alterate parameters and activate or deactivate mesh and material in the lx* files automatically.
No problem with this.
But how to save time, rendering hundreds of this variations (searching for a good one to render with all the "bell and whistle"), considering I'm only interested in visualizing in high resolution the placing of mesh with no particular lighting or materials?
I will like something like a technical drawing with very limited or no shading to render in -seconds-. Something to render in less than a second would be a bonus (Little realistic, I know)
I have to say that I use only luxrender lx* files to work and I can't made a simpler scanline render with, say, blender, because I generate directly lxs sourcecode. So I'm forced to find a method for render very fast previews with a very photorealistic, very "slow" umbiased renderer! Only one of the great ideas of mine.
Please fill this thread with ideas and settings if any! Please consider how much I hate noise, so a solution like "render with any settings for 2 seconds and live with all that noise" it is non acceptable

[A-man]

I'm sorry, but I really don't think you'll find the answer to an under 2 second render with Luxrender. SLG might get you a decent result in 20 seconds or so (depending on resolution), but you'll need a high end graphics card, and then you also can't use the lxs file.

[Vasjly]

Thanks for answering A-man! I have to admit I made a difficult question, Luxrender it is surely made to make differents things and I try to force it doing what It cant do. But this may even be funny, so I'm not losing all my hopes. I have to find a solution, in any case (It is for the future of the mankind, afterall).
So, after a irc chat on the #luxrender irc channel with LordCrc, paco007 and homer_s, it seems to be a closed route, even if they provided some useful tips like exporting meshes as ply to reduce loading time for the scene.
I think, but I'm not sure it is feasible, that if in a scene without any lightsource, if every objects could be made slightly emitting and if the light every object emit can be individually or globally configured to not affect any other objects, I will have something usable without large rendering time...
I'm surely wrong, obviously. It is very possible the option to make a light or emitting object not affecting shading of the rest of the environment not exist.
For sure I cant find it in the doc and in Google. After all, it is too anti physical to be implemented in a physically correct render engine...

And if I made a challenge? Who can make a scene with some cubes capable of rendering without noise and fuzzy border in less than 2 second loading time apart?
The cubes (or any other object/geometry you like) have to be clear and visible, antialiased maybe, even without any shading or projected shadows. Colors are not important, contrast have to be acceptable. More emphasys to the edges would be super, but not necessary to win. Who will take this challenge? I am a novice to luxrender but from the little I learned and tried this is more difficult (or impossible) one may think...

[Abel]

if every objects could be made slightly emitting and if the light every object emit can be individually or globally configured to not affect any other objects, I will have something usable without large rendering time...

Probably, but this would have absolutely nothing to do with physically based rendering. In LuxRender this is not possible, even though I suspect that there are some developers around here who could code that kind of a renderer within five minutes.

[Vasjly]

Ok, then I have no other way to look at the code and try to make this feature myself. For sure it will take me longer than five minutes. Maybe, five weeks? five months? If someone would join in my quest it is welcome. Some previewing features would not hurt luxrender and may be useful for someone, I think.

[Dade]

Have you tried the directlighting rendering mode ? It is old school Whitehead-like ray tracing and should be pretty fast on modern CPUs.

[Vasjly]

Hi Dade and Abel. I'm trying with directlighting rendering simple poligonal geometries and single point light source. Render times are considerably high even with this setup (20 seconds to acceptable results with PAL resolution). Some other tipes of light sources are most efficient? Light strate set to auto, max dept to the minimum (8) shadow ray count to 1. Accellerator is QBVH, I dont yet understand its advanced settings. Sampler set to metropolis, I see room for improvement here but not yet identified a good (fast) combination for the sampler. Ah, clayrendering activated testing from luxblend.
There is some magical super imprecise but super fast denoiser to be activated somewhere?

[Dade]

Sampler set to metropolis

MTL is probably not the right choose for this kind of rendering, try to switch to LowDiscrepancy Sampler, for instance with 16 or 32 samples and and haltspp condition set to 16 or 32 too.

[J the Ninja]

Sampler set to metropolis

MTL is probably not the right choose for this kind of rendering, try to switch to LowDiscrepancy Sampler, for instance with 16 or 32 samples and and haltspp condition set to 16 or 32 too.

Sometimes if you set haltspp and pixelsamples to the same value, it might not realize it has to stop until after the pass and winds up doing 2 passes, so I usually set haltspp a bit lower (ex, 15 or 30)

[Vasjly]

Thanks Dade and J the Ninja, I've applied your suggestion, but yet relative high rendering times. Something more to look at?
If only a switch could be made to temporarily turn off physical accuracy could be made... Let the case (not mine, as explained) of some forgotten exported xl* code scattered in the user hd. How to tell quickly the contents if filenames is not of help? Open in the gui, check preview box...
And another situation where fast previewing would be useful: generating thumbnails in graphical files manager like nautilus, thunar and other for xls files.
Ok, stop begging