Sunflow Open Source Renderer

[kubabuk]

but anyway SYmek, could you post approximate render times and res for these images.

thanks

[symek]

Ladne!

Could you please tell us more about advantages of sunflow speed over mantra - do you think it's much faster? What is your impression, is it a good way to follow in the future, or rather a little bit cumbersome to work with? How about exporting shaders, there isn't easy, straightforward way to translate them to sunflow...?

kuba

Czesc Kuba!

I'm not the best person to evaluate SF. I'm pretty fresh in it and I wouldn't go its way in production except one really good reason which force me to prepare this exporter.

Although I'm very impressed with SF development (specially that this is one man project and it's written in Java) for now this is completely unusable software at least in sense of reliable solution for any expected result in production. This is of course alpha version. It's hard even compare SF and Mantra. There are things which happen much faster in SF but this stays true as long as you don't deal with, lets say, heavy geometry, with motion blur and ray traced reflections. Than things still can go fast but... lets assume again that you're unsatisfied with AA and you'd like to increase its value... and than rendering time jumps 10x! You never know! This is a problem. Unpredictable...

So... these environments are too far away from each other to find any relation.

Area lights are extremely fast for example, There are at least 6 GI algorithms with number of speed up settings, there is build in image based lightning. There are physic based camera/lenses model which gives, again, nice and unusable results since sampling overhead to be done for it.

The main issue for now, as I think, is various problems with sampling/filtering. And this is of course main challenge of any algorithm programmer nowadays. You see, all light related phenomenons are pretty well described and what people really straggle with is how to turn these goodies into a nice, smooth pixels. Mario, I suppose, can say much about it. Beautiful glass rendering turns your life into a nightmare when animated. There could be so many artifacts in its fancy-ray-traced-with-caustic-surface.

As to shaders: SF simple uses Java and its API to define shaders. There is a bunch of build-in shaders. Plus you are free to write your own in Java. SF will call Janino, its own Java interpreter, to compile and execute it. This pushes SF shaders into mental ray route where if you don't like to write C++ code, you must use something like RenderTree in XSI which is, as I understand, set of tiny predefined shaders ready to combine in one big daddy. So there is not straight way to translate shaders between mantra and SF.

Please note that all I said here was in a good faith but I'm not a SF expert, SF is in alpha stage and in spite of its all early limitations the future is bright, err... orange.

cheers,

sy.

[symek]

The good side of renderers like this is that it is really simple to set up a scene to render, just add a few light bulbs or the sun position and you're set to go. The down part is that to make "tricks" like a diferent light falloff, soft shadow maps, etc. it is impossible (please correct me if you can in Sunflow).

You are absolutely right, Andz!

Literally none of a standard rendering tricks - like separating lights per objects, rendering shadows in passes. Well, to be honest you can not even render with alpha channel in SunFlow right now. But, again, this is an alpha version.

(On the other hand some features like porcedural scene building with java api potentially turns SF into little more advance tool in a future).

sy.

PS Kuba:

rendering times was: from 2 minuets for arealight example, up to 2 hours for DOF example. GI with lighting geo took no more then 5 minutes. Motion blur (this is camera motion blur) took 4 minutes but sampling was to low and I used median after ). GI, sky light, IBL are pretty fast. DOF, MB are extremely slow due to sampling/filtering. Wonna try ?

Edited June 26, 2007 by SYmek

[kumpa]

hi symek !

if possible, i would very much like to try it.

kumpa

[Andz]

You are absolutely right, Andz!

Literally none of a standard rendering tricks - like separating lights per objects, rendering shadows in passes. Well, to be honest you can not even render with alpha channel in SunFlow right now. But, again, this is an alpha version.

(On the other hand some features like porcedural scene building with java api potentially turns SF into little more advance tool in a future).

Well, to be more clear on what I said.

If you need tricks, all you have are the same tricks a photographer has... light gels, bounce cards, umbrelas, etc... you have to build it all in your scenes ;-) You also have to know your way into camera aperture, f-stops, film exposure, etc...

I guess is not as easy as I mentioned.

[symek]

Small update:

Houdini classics: varying instances inside SunFlow.

4500 points x 1000 instances = 45 minutes...:

300 instances with shaders varying = 7.40min (AA is too low, whis is why time is ok)

I'm almost ready to share it,

cheers,

sy.

[Andz]

Looks great, and render times even better!

**edit** Nice to see that you're even able to export colors on instances

[symek]

Looks great, and render times even better!

Nive to see that you're even able to export colors on instances

Every instance have its own shaders, but still this happens automatically and has no important impact on render time.

[symek]

Done for now.

Sunflow for Houdini 8

bon appetit!

cheers,

sy.