Building Meshes Wait Time

[TKasz]

I am rendering a stage using Twilight Render with Sketchup Make 2017. I am using the High+ Preset and rendering at 4k with 10 threads while using volumetric lighting.

The render has been active for the past 152 hours and it was mainly "Shooting Protons". For the last at least 6 hours, it has been saying "Building Meshes (100%)". How long will this step take, or is the render broken? I wouldn't be questioning it if the progress bar was something not 100 and moving, but it has only been at 100%.

[Fletch]

Welcome Tkasz

Number one beginner mistake is to choose the highest render setting render at high resolution and "hope for the best".

If you have not tested the scene at low resolution with lower render setting, it makes no sense to jump to the highest settings right away.

152 hours? I don't render anything that takes longer than 2 hours. Mostly anything I render now takes 15 minutes.

Please share the scene using a file sharing service like dropbox, and we can advise better. With no information about the scene, it would be a completely wild guess what is happening.

Please watch our video tutorial series: 6 Essentials To Rendering with Twilight Render linked in my signature below.
Please follow the Pre-flight checklist before you render anything.

[TKasz]

I have a bunch of lights in it and I have a custom texture. I rendered in low at 800x600 and it took about 5 hours. It didn't stick on this step for this long though. I will share file when I can.

[Fletch]

There are clearly several things wrong with the scene.

Did you purge the file and follow all the Pre-flight checklist steps?
Did you watch the 6 essentials video series?

[TKasz]

Attached is the file. I did a medium+ render at 480x360 and it took over 20 hours.

https://www.dropbox.com/s/lagll5lm9rmyl ... e.skp?dl=0

[Fletch]

I asked you several questions and you refused to respond to my questions.
How can I help if you do not respond to my questions?

There are many problematic issues with your scene.

1. Number of Lights
2. Resolution of Textures
3. Light emitting curved surfaces
4. Required use of Easy 1-7 render settings (Photon Map render settings) due to using Volumetric effect.
5. Make Repetative Objects in Scene into Components.
6. The light fixtures you have built you did not test individually inside of a simple box scene, and therefore none of them work.
7. see below for more

In first analysis we go to:

Extensions>TwilightV2>Diagnostic Report
Diagnostic>All

Here we see a problematic texture that is likely a major culprit. 28440x3888 pixels. This is a ridiculously high resolution texture in any rendering setting and completely unnecessary.

Step 1: Reduce High Resolution textures
Open any texture over 4000 pixels and reduce it's longest side to be no greater than 4096-3840 pixels. The smaller the texture, the faster it will render.

Why?
The engine has to calculate the bounce of light off of each sample of pixels in a texture. You have 1100 lights, and a texture 28000 pixels in length, the fact that the engine can calculate any image at all is an amazing testament to the robust programming of Twilight Render.

What's more, you have made this material an emitter. So now it has to analyze the light coming from billions of pixels.
It is astounding to me that it renders anything at all.

I used SketchUp to export the png image file in each case and make it 2400 px wide instead of 28440 px wide. Saved the file, and it was automatically reloaded into SketchUp.

Step 2: Purge the scene
Purge of the scene got rid of 15 materials that are not used and 7 components.
If one follows the pre-flight checklist is requires purging the scene


Step 3: Change all emitter surface materials to "fake" style emitter
Next, when rendering with Easy 1-7 render settings emitter materials slow render times greatly. You must set all emitter materials to "fake" to great shorten render times.

Lastly, with over 1100 lights, the Easy 1-7 render settings at default will not work well for your scene. These settings are optimized for normal architectural renderings. Your project is far from the normal architectural interior which is something like a bedroom, living room, or kitchen scene.

Any scene with more than 20 lights is considered a lot of lights. Your scene contains 1100 lights, and also adding the emitter surfaces more like 2000 lights. So you will need optimized settings for your scene, unless you simply render with Easy 9 or Easy 10 render setting (which unfortunately doesn't work with the volumetric material).
The fact that your scene is using the volumetric material that requires Easy 1-7 means that you will need a custom light sampling setting.

Step 4: Try custom render setting attached below (save the unzipped .xml file into the folder: C:\ProgramData\TwilightV2\RenderSettings)

We need to have the photon shooting for the entire scene to be somewhere in the 100k-200k range, keeping below 1 million. The photon shooting in the Easy settings has to assume how many lights are in the scene, and so the photon shooting for a scene with more than 100 lights is going to be way too high.

Even after all of these changes, however, processing the scene is painfully slow. So there is still more to fix.

The next major problem is that you have many repeting objects in your scene, and yet they are only "groups" and not components. If they were components they would export and render much more quickly.
This demonstrates that the potential of SketchUp's components are not being realized in your scene, and you are really slowing down your ability to make quick progress in SketchUp and in Twilight Render.

Utilizing a plugin called "groups to components" I converted many of the group copies into components. But it would take too long to truly fix all of the mistakes with non-component groups in the scene.

Using components instead of groups for repetitive elements is critical in SketchUp and with most rendering engines including Twilight Render.

Until the entire scene is properly componentized you will definitely have problems with it.(every repetitive object is a component instead of a separate group)This is a SketchUp modelling issue, not a Twilight Render issue. But they are related.

A professional workflow: Always make a small test room and optimize each of your lights before you add a thousand of them into a space and try to render at 4k resolution. If a single light doesn't work in a 3 meter cube, why would it would work in a stadium? None of the lights were shooting any light at all because of many problems with how they were built.

You have placed glass over all of your lights, and you have placed light objects adjacent to geometry like the surfaces of the light fixtures. Delete all glass, it makes no difference in this scene. Move your light objects away from adjacent geometry - they are rendering as black because they are inside of the light fixture geometry.

You have 26 light objects inside of a spot light. They could probably all be replaced by a single spot light just below the fixture, and 26 small fake light emitting surfaces to represent the "look" of the 26 lights. It would render lightning fast.

Use the parking lot preview scene to view how the lights will work in a big space

Disable soft shadow for all lights, as with this many lights soft shadows will take a very long time to calculate and with spotlights such as these, soft shadows are not important.

See attached light test scene to help you further your experimentation.

[Fletch]

First, let me say that this is a massively complex scene you have chosen for your first rendering and you need to break it down into small pieces and learn to do a small bit/scene first before you can work your way up to creating this scene.

After all fixes above, it still takes a long time to process the scene. Likely because there's a thousand components. But definitely it processes faster after carefully creating components out of all repetitive objects and fixing all the lights.

[TKasz]

1: This is nowhere near my first render. I have been using TR for over 3 years.
2: I never "refused to answer" your questions.
3: I want the LED screens to be an emitter, because that is literally the point of LED screens.
4: I have some glass selected in the materials editor, and some is frosted glass in there as well.
5: I used a lower quality texture before and it looked below my standards.
6: I did purge about 3 times.
7: The lights worked, as by me saying I successfully did a 480x360 render.
8: Some of the lights that have 26 lights in them have multi-colored rings, not possible with 1 source per light.

[TKasz]

I did the exact same settings with these renders besides having volumetric, and in High +.

Same fixtures, same techniques, and these weren't even purged when I rendered them, they were just done with interior+.

[Fletch]

Scene processing time is down to 1 hour now. (after converting all similar groups to components).

That volumetric material will not work with light emitting surfaces and also with over 1000 lights will take an enormously long time to render.

In tests the spot lights shared from the scene rendered black - the light objects were needlessly behind double layers of glass making no effect on the rendering except to slow it down and the spot lights z-fighting with inside geometry of light fixtures were not rendering properly. They were conflicting with geometry leading to artifacts and long render times. After implementing the recommended changes, they rendered much more quickly... in mere seconds. (not testing with volumetric material)

My apologies - I assumed it was your first rendering, because so many things in the file looks like it's a first-time rendering.

Yes, I suggest rendering this scene with Interior 10 or 9. you can use the new glow post-pro in the render dialog post-process tab for some effect, but you will have to photoshop the volumetrics from the spots, as the volumetric material doesn't work with Easy 9 or 10. Nor with light emitting surfaces.