POV-Ray Question

[nxtstep101]

I recently found out about POV-Ray and am going to use it to start making HQ renders of my LDD models. I only have one problem: whenever I try rendering it ends up taking a super long time, so long in fact that I end up having to cancel the cycle. The longest I've tried letting it run was for ~36 hours, and it only rendered 60% in that time. Is it normal for it to take this long?

And just in case it is needed I have included the LDD of the model I am attempting to render.

gbc_dual_arms.lxf

[Phoxtane]

Yes. Raytracing-based methods of rendering are horrendously CPU-intensive and as such the entire process's time depends entirely on your processor speed and the amount of processor cores available to do the work. If I'm understanding the article correctly, raytracing involves calculating the path of light through each pixel in an image and simulating the results when it collides/refracts/diffuses/whatever - and the bigger the image, the more pixels. Transparent parts, I've found, are awful for this because of all the ways that light interacts with them!

[papacharly]

The time which is required for rendering is marginal dependent on the part count of your model. Even models like the ucs millennium falcon (more than 5000 parts) can be rendered in appropriate time by povray. So 277 bricks are no challenge for povray at all.

I assume that you have extremely high quality settings in povray. This can be the reason for exceptional high time consuming renders. So try to lower the quality settings and check if you are satisfied with the result.

More or less all of my renders (see my Flickr) were rendered in appropriate time. Let’s say 1, maximum 2 hours. For me the quality is fine. And my PC is definitely no heavy duty data processing center. Its just an old box …

[Calabar]

Pow-ray is a free software, but unfortunately is very slow. Even the version 3.7, that supports multicore CPU (v3.6 don't) is extremely slow if compared with other modern rendering software.

For example The user virtualrepublic here shows hight quality rendering obtained using MODO, a commercial software, in very short time. This is one of his entries.

The rendering time increases with model size but overall with the presence of transparent parts.

Anyway there is some trick. The user bbqqq discovered that you can split the rendering in three parts (geometries + bevels + shadows) and assembly that in a single image, saving a lot of rendering time. Take a look at here.

[legolijntje]

Pow-ray is a free software, but unfortunately is very slow. Even the version 3.7, that supports multicore CPU (v3.6 don't) is extremely slow if compared with other modern rendering software.

For example The user virtualrepublic here shows hight quality rendering obtained using MODO, a commercial software, in very short time. This is one of his entries.

[...]

Yes, it's true that POV-Ray is quite slow compared to modern alternatives such as MODO. But, don't forget that Virtual-Republic had a someting like a Dual-Xeon for a total of 24 cores or something like that. That also makes a difference

Another tip for nxtstep101: transparant parts take a lot more rendering time than not-transparant parts, also something to keep in mind.

[Nachapon Lego]

- Fast radiosity is much faster.

- Many technic parts with all bevels always very slow (many polygons).

- Original LDD geometry is super fast. (less polyons)

1st 2 min rendering time.(Original LDD geometry)

2nd 30 min rendering time. (all bevels)

nxtstep101 's gbc_dual_adrms render 2 min by Nachapon S., on Flickr

nxtstep101 's cgbc_dual_arms render 30 min by Nachapon S., on Flickr

Edited January 3, 2015 by bbqqq

[nxtstep101]

Ah, so I was trying to make it way too high quality. Thanks for the help guys, and thanks bbqqq for giving me examples.

[nxtstep101]

I have another question regarding POV-Ray, and instead of making a new topic I'll just post it here. Where in the settings can I zoom in on the model? And is there anyway to preview how it will look be positioned before I start rendering? Thanks.

[roland]

I have another question regarding POV-Ray, and instead of making a new topic I'll just post it here. Where in the settings can I zoom in on the model? And is there anyway to preview how it will look be positioned before I start rendering? Thanks.

In the top left you'll find a drop down box listing resolutions, set it to one of the lower(non aa) ones for test rendering the camera / position etc.

You can also add new items to that list for custom render quality settings by editing the corresponding ini file.

[nxtstep101]

In the top left you'll find a drop down box listing resolutions, set it to one of the lower(non aa) ones for test rendering the camera / position etc.

You can also add new items to that list for custom render quality settings by editing the corresponding ini file.

Thank you, that helped me a lot!

Edited January 10, 2015 by nxtstep101

[nxtstep101]

I have another question: Is there any way to have a model display shadows even when the background is completely transparent? Thanks.

[nxtstep101]

Also, why whenever I render a dark color model and set the background color to white it always makes it a dark gradient instead. Any idea on how to fix this?

Edited February 11, 2015 by nxtstep101

[roland]

I have another question: Is there any way to have a model display shadows even when the background is completely transparent? Thanks.

I don't think so, shadows need to be cast on something so without a floor you'll only get shadows on other parts etc.

Also, why whenever I render a dark color model and set the background color to white it always makes it a dark gradient instead. Any idea on how to fix this?

Do you mean the model it self appearing gradient or are you getting the wrong background color?

If it's the model it self it's the result of your lighting settings, But I don't know what would cause a wrong background color though.

[nxtstep101]

I don't think so, shadows need to be cast on something so without a floor you'll only get shadows on other parts etc.

Yeah that's what I figured. Although, I did figure out how to include the shadow while keeping it transparent, but it required me to edit the picture a little in gimp.

Do you mean the model it self appearing gradient or are you getting the wrong background color?

The wrong background color. I tried the same thing with different color bricks and it displays the white background perfectly. For some reason it only seems to affect dark colored bricks... Not sure why, though.

[sama]

Hello, I have a question. I have been running this 59-pieces model render for 3 hours:

However, the pixels per second is dropping ever minute or so. It was at 700 initially, then 100-ish when it came to fine tuning rendering (taking out all the squares and adding fine curves). And now it is at 40. I am totally new to this, and still need to see how this specifically works. Can someone tell me how to reduce rendering time? Like, where do/what do I enter to change quality settings? Also, how to I get different backgrounds? I am running this on default settings btw.

[sama]

Okay. So now my pixels per second dropped to 31, and i am only 50% done this little model. Why is my pixels per second rate dropping?

[Umbra-Manis]

First of all we need to know what settings you used on the LDD2POVRay converter. Models usually take longer as they move along, but weird setting can really slow it down.

[Lego Otaku]

Also what computer are you using?

[sama]

First of all we need to know what settings you used on the LDD2POVRay converter. Models usually take longer as they move along, but weird setting can really slow it down.

Okay. So I just got the LDD2POV converter the day I rendered the little 59-piece model (which btw finished rendering in 9 hours). I did not change a single setting, used it on default. What settings do you recommend? How do I change the settings for quality and how can I change the background color? Sorry for the bombardment of questions, but I need help/advice with this.

Also what computer are you using?

Using a laptop, 2.2 GHz CPU (4 threads). I know its not the fastest or best, but it is quick enough for single application use. When I was rendering, no other application was on/active. However, POVray kept on saying that one thread was in use. Why didn't it use all 4 threads?

Edited March 1, 2015 by sama

[Umbra-Manis]

The single biggest setting is the Radiosity, which by default is set to Custom. Custom is slow, so i use the Default setting for basic renders and Final for big images. Also you can uncheck the shadow box on the top light (Number 3).