POV RAY

Vindic8ed

I just started using this to render some pictures for models I have built but I'm struggling to figure out how to get it to do what I want to do. The first file rendered at a weird angle so the lighting was reflecting off it like crazy. I tried a different model and it rendered perfectly. I did a third one and it made a really small render of it.

I was looking through the help menu to figure out camera angles and stuff but if you are using the cmd how are do you figure out how close/far you want the picture or what angle you want it at without actually seeing it?

Good (2nd) Render:


Small (3rd) Render:

rancorbait

It's simple, POV-Ray renders the model in the same position as you last saved it in LDD :)

Vindic8ed

I figured that's how the first second one came out so good, so I went and saved the rest of them in positions that I wanted, but if you look at the tree in the post above it came out really small and and poorer quality

rancorbait

I'm not sure why that is. Perhaps you accidentally adjusted the image size under the "Rendering" tab?

Vindic8ed

That's possible, I don't see anything anywhere that says what the image size will be though. (Thanks for the help)

Vindic8ed

Nevermind, I found a drop down menu above the messages that had the resolutions. Anyway to use the files already created to render it faster or does it have to go through the whole process all over again? It's going really slow for some reason, I don't think it's using my graphics processor to do it (I have a really nice one but it's only rendering 27pps?)...

I can't seem to find an actual settings page that shows stuff like that.

rancorbait

Oh, I was referring to the settings in the LDD to POV-Ray Converter window.

I don't think it would make much of a difference, POV-Ray is just slow :)

plasmodium

http://www.povray.org/documentation/view/3.6.0/183/

According to this, graphics card quality doesn't affect POVray rendering time. It's a little daft, as you'd expect it to, but their's not to wonder why and all that...

binaryeye

Vindic8ed said:

I figured that's how the first second one came out so good, so I went and saved the rest of them in positions that I wanted, but if you look at the tree in the post above it came out really small and and poorer quality

I haven't used POV-Ray in about 15 years, so I can't give any specific advice. But in the image with the tree, all of the edges look aliased. If there's an option for anti-aliasing, turn it on. This will likely increase the render time, though.

Vindic8ed

Thanks! I was able to figure out the resolution problem. I still don't understand why it's going so slow though. It's using 95-100% of the CPU and 2gb RAM (of 16) and no ohter programs are being used. Sometimes it will be rendering 2000pps and other times (the last hour...) it sits around 70pps. =(

leemcg

One thing if you're trying to just change the position and view in LDD, note that if all you do is open a file in LDD and change the angle of view, LDD thinks you haven't actually changed anything in the file so doesn't bother saving when you choose save. You need to move a brick (and then move it back) too.

CCC

Vindic8ed said:

Thanks! I was able to figure out the resolution problem. I still don't understand why it's going so slow though. It's using 95-100% of the CPU and 2gb RAM (of 16) and no ohter programs are being used. Sometimes it will be rendering 2000pps and other times (the last hour...) it sits around 70pps. =(

If you are rendering blank areas, then you will get a very fast rate. The rate will vary depending on what light operations are being processed.

Vindic8ed

Thanks!

Vindic8ed

It's still a little baffling that the GPU can't be used to take a significant load off of the CPU though. When we do "network security" the GPU is used to crack passwords. The USAF built a supercomputer for imaging from PS3s and some scientists recently used PS3s for studying/calculations for Black Holes.

rancorbait

CCC said:

Vindic8ed said:

Thanks! I was able to figure out the resolution problem. I still don't understand why it's going so slow though. It's using 95-100% of the CPU and 2gb RAM (of 16) and no ohter programs are being used. Sometimes it will be rendering 2000pps and other times (the last hour...) it sits around 70pps. =(

If you are rendering blank areas, then you will get a very fast rate. The rate will vary depending on what light operations are being processed.

Right. And areas with transparent parts are extremelyslow.

VorpalRyu

@leemcg, another trick is use the hide tool, even if you click the reveal button, it still has the save button as active, I use that trick all the time.

On a related note, does anyone here know what tools people are using to create the image work for their custom minifigs for their LDD images over on Lego Ideas? I was going to just go with having the basic colours on any minifigs for projects that would contain them.

VorpalRyu

On the topic of POV Ray, I'm currently rendering my Microfighter designs & was wanting to speed up the process without dropping image quality, any tricks that should know about?

Ra226

To answer several questions in this thread, POV-Ray does software rendering only, so no, your vid card won't help.  It's strictly CPU power.  And I don't recall if it's multi-threaded, so it may be raw GHz power (as opposed to how many cores you have).

As you found already, there's a drop-down menu to modify resolution and whether or not edges are anti-aliased.  But if you want a different resolution, you can select "more resolutions..." and a help file will pop up showing you how to modify a text file to add more.  Personally, I use 800x600 non-AA for rough rendering, then I'll do a 4k AA render for final image.

I use MLCad (which makes LDraw compatible files) to make my models, and then a small command line app, l3p, to convert to POV-Ray.  That app defaults to 30 degrees up, 45 degrees over, and zoomed out just to point where model fits in screen.  The command line app has options to manually set a camera angle, as well as define light positions, colors, and intensity.  You can see some of my renderings here (shameless plug!)

Lastly... I don't suppose you'd want to send me that world map file--I love it!

VorpalRyu

Found that the LDD to POV-Ray setting of Radiosity to Custom was causing the issue, even #30162 Quinjet was like 2 hours to render. Was just after quick & dirty renders for this stuff, so I'm using Normal for the moment, I'll have to use Custom for my Lego Ideas projects, but for that, I may have a comp on offer, so I don't have any down time.

jwsmart

I gave a presentation on this stuff a couple years ago at Brickfair VA: http://www.ilugny.org/presentations/ (It's at the bottom of the page).
I also posted some of the images here: https://www.flickr.com/photos/51436400@N05/sets/72157634980762274/ 

Around slide 20 I start talking about using masks to speed up rendering of transparent parts - which is something that I learned from a flickr/eurobricks user: https://www.flickr.com/photos/nachapon 

General comments on performance & POV-RAY preferences:

I like Outdoor HQ as a radiosity setting in LDD2POV - it's a good balance between quality and speed.  

POV-Ray is a very old piece of software - 1991 actually - it predates all this newfangled GPU rendering by a couple decades or so.

POV-Ray is multi-threaded though, I think by default it uses one thread per core, which is probably fine.  

If you have a system with lots of threads and relatively poor single threaded performance, I would set Render_Block_Size=8 - that will ensure each core does little bits of the image.  I've found that on a really complex render with lots of transparency, it can sit at 99% for a long time trying to figure out a single block. 

I use Render_Pattern=3 so it renders the image from the inside out - I usually can tell if something is wrong earlier that way.

I've heard that POV-RAY's anti-aliasing is terrible - it's better to just render the image at 2-4x the size and scale it down using your favorite image editor (Paint.net is pretty useful)

This page is great:
http://wiki.povray.org/content/Reference:Tracing_Options


Hope some of this is useful!

Ra226

Those are some great tips, @jwsmart--thanks!  

VorpalRyu

Does anyone know the settings to needed to create a model with no shadows or reflections? Need to render some models for the database, but the Morro Dragon looks like hell, massive amount of reflections occurring, that obscure it.

Ra226

^ Lots of light sources helps get rid of shadows.

iso3200

@VorpalRyu At the start of your .pov file source code, you'll find the general settings (before the Model Bounds information) Just change the declarations from 1 to 0 to turn off shadows, floor, reflections etc. You'll be looking for the lines below (or similar)

// Generated By: LDView 4.1 (C) Travis Cobbs and Peter Bartfai, 2009
// See: http://ldview.sourceforge.net/
// Date: Mon Feb 23 13:41:31 2015
// Input LDraw File: your_file.ldr
// LDraw File Author: Your Name
//
// This file was automatically generated from an LDraw file by the program
// LDView.  See comments above for further details.

#declare LDXQual = 3;    // Quality (0 = Bounding Box; 1 = No Refraction; 2 = Normal; 3 = Stud Logos)
#declare LDXSW = 0.5;    // Seam Width (0 for no seams)
#declare LDXStuds = 1;    // Show studs? (1 = YES; 0 = NO)
#declare LDXRefls = 1;    // Reflections? (1 = YES; 0 = NO)
#declare LDXShads = 1;    // Shadows? (1 = YES; 0 = NO)
#declare LDXFloor = 1;    // Include Floor? (1 = YES; 0 = NO)

Ra226

...or what he said ;)

VorpalRyu

@iso3200, thanks for that, I hadn't considered poking around in the pov files, I'll have to give that a try. :smiley: I took a look at the ini files, but I figured the pov files would have been raw rendering data. Awesome.

iso3200

If you're on a PC it might be worth looking in your .ini files - I don't use them on a mac, but they basically do the same thing with switches and options. I'm not sure if the .ini overrides the .pov or vice-versa, but the above should give you a rough guide what to look for.

VorpalRyu

No luck there, data is not present in the ini or pov files. @iso3200, should LDD to POV-Ray have the same declarations in the one of those files? Or could it be in one of the files they declare?

iso3200

I think the problem is that we are both using differnt platforms, and I guess LDD to Povray writes things differently.

On a Mac, I design in Bricksmith, then open the file in LDviewer to set my camera angle and position. This writes to one .pov file with no extra includes or ini files, so it's kept very simple and I can tweak all the code at the beginning if needed.

LDD to Povray must do something similar but maybe it uses it's own variables. I Googled and it looks as if you just simply turn the shadows off by unchecking the shadow box next to the light source, or setting them very low.



You may be able to kill some of the reflections by increasing your ambient light.

However, removing the shadows and reflections will leave you with a very flat looking image.

The best guide I found to get started was at Eurobricks

Note that this also uses LDview to make the .pov file, and the export options are there to include shadows/reflections etc. If you follow this method you should get the code I pasted above.

Sorry I can't be of any more help.

iso3200

Just noticed over on Eurobricks, there's a new rendering program for LDD called Bluerender. It's a young program, but it certainly looks like it could go far. Seems to have the speed the POVray lacks, even if the renders are not quite as nice (at the moment)

Bluerender

iso3200

Sorry - just realised again you're using LDD - I don't think LDview opens LXF files. Perhaps someone with experience of LDD to Povray could chime in, instead of me keep confusing the issue :blush: