Blender vs. Luxrender

I finally found some time and motivation to do a project I had long in mind.

The initial idea is to have the same scene with the same set of textures taken and optimize the shading and lighting for blender and for luxrender.
Doing this should help me to learn the workflow necessary to work painlessly with luxrender.

The style is targeted to be photorealistic, which should be obvious to achieve with luxrender and quite hard with blender internal renderer.

I start now this thread with the scene having already a basis for the the blender optimized setup. Depending on the feedback here I will further improve the shading/lighting while at the same time starting the luxrender part.

I will open a thread at the luxrender forum as well, where I hope to get good advise of how to setup the various materials, especially those settings, which have no corresponding implementation yet. ( e.g. SSS).

In the course of preparing this project, I recognized that this is also the perfect opportunity to implement a linear workflow, which is essential to get nearer to photorealism with BI.

If all goes well, I intend to write down my findings in a short tutorial/howto.

So, here is the first render

Blender internal/Compositor, no postpro
Render time: 43 sec ( AMD Phenom X4 2,3 Ghz, 8GB RAM, 64bit blender, Linux)

Beautiful first effort, lovely color and saturation, look forward to your developments.

Yeah that’s really nice. 43 seconds is a nice render time too :slight_smile:

I’ve been looking into luxrender a bit recently. I think the mattetranslucent material will give you decent SSS results but you’ll probably need another copy of the snail body but with a colourless glass shader to get the specular highlights.

Thanks for the tip, I will give it a try. I just read at the luxrender forum that radiance has SSS and volumetrics high on the list for the 0.7 release

As I think it may be of interest for others I have written a short abstract about using a linear workflow in blender under linux. You can find the entry here.

I did some tests today to get better displacement maps and normal maps out of the diffuse maps ( another howto coming … ) and will post the results later.

This work is really great. Am looking forward to its tutorial.

Great Loramel. I am trying to implement a linear workflow too. I have one question, as I read your overview. Do you use the gamma node at all? There is a neat thread over in the tests section where people talk about using this for gamma correction within Blender. If you could tell me that would be great.

Cheers and God Bless.

In my setup for the current project I do not use the gamma node at all, but it gives the same results as far as I have tested it. To get proper gamma correction it may be wise to use the dedicated gamma node instead of the RGB Curves.

I was wondering if you were planning on releasing this .blend cause I wanna play too…

Just asking because I was checking out your site and it looks like you do normally release your works. I think it would be kind of fun to have a challenge of sorts to see who could get the most photo-realistic rendering out of this scene.

Either way, it’s all good…not trying to peer-pressure you or anything.

Yes, as with all my projects this one will be available too. I usually make it available for download after officially declaring it finished i.e. posting it in ‘Finished Projects’.

Just have a little patience until my luxrender setup is done too, which hopefully doesn’t take to long.

Right now I am in the final stages of finalizing the scene setup and blender internal settings. After that I start with the luxrender part. I will post an updated image later today.

Well, now I have finalized to scene setup and all textures as common base for blender internal and luxrender.

Attached you see my final render for blender internal. I added some displacement mapping to the mossy floor and did some final tweaks.

rendertime on this one is 1:14 mainly due to the displacement mapping on a high subdiv’d ground plane.

Now lets go on the see what I an achieve with luxrender.


wow! looks good! i’ll be watching over this thread :slight_smile:

I’d say the B.I render looks better.

I think the snail’s body is perhaps a little too light, maybe too much SSS? Part of the problem will be that a real snail is essentially volumetric - it has areas around its face and under the shell that transmit less light internally.

However, I think it could probably just do with being having a little less transmittance or reflectivity. Also, a spec map on the shell might give it a little more definition.

Well, … right now there are only B.I renders … :eyebrowlift2:

Luxrender will come next.

Thanks FishFace. You are right about a snail being volumetric. You see all type of organs shining through. I haven’t found a way to simulate this with B.I.
There is already a spec map applied to the shell, but you are right that the effect is maybe too small.

well nice SSS for the snail.

The light setup is nice - what did you use?

Before using a linear workflow I was using about 6 lights and was still not satisfied.

Right now I’m using a spot with buffer shadows as key light, a hemi as fill. AAO is used only in sub mode.
I tried a trick with the material on the mushrooms and snail shell, which I think endi was using in one of his posts, where I use an angular environment map from a forest in two textures slots, one mapped to reflection and on to normal to simulate GI specular and diffuse shading. The effect is subtle but helping.

See attached the actual scene setup.


How did you setup your workflow for linear working?

So you use AAO and hemi together? Dont they basically do the same while AAO adds object proximity shading.

Again that snail SSS is looking good, I wish the SSS could also take care of SSS of impacting shadows. Well it would not render that fast than anymore…

see here

So you use AAO and hemi

I think they are similar. With a hemi I have direction too, which sometimes offers more control over the shading besides being able to restrict it to diffuse or specular only or make it affect a layer only.

AAO is here only used to introduce darkening due to proximity.

This looks very good so far. The work you did on the material really shows. And it also shows that BI is capable of very nice renders provided a corrrect workflow is adopted. I’m currious to see the comparison with LuxRender.

I’d say the tone balance in the shadows is a bit too dark and generaly, the contrast a bit too high. I’d adjust the tone flatening curve. But it may not be just a linear workflow issue. I think that in a forest, even the shadow side of objects would still receive more environment light than what your setup gives.

Also, I’d suggest you try the Gamma node and compare the results. My experience with RGB curves is that it is very difficult to get a good gamma curve equivalent even in Photoshop where I can enter numeric values for the curve control points. I tried to get a decent gamma curve with the curve node in Blender but not being able to enter control point numeric values, I only more or less achieved it through a lot of fiddling.

You make a good job of evangelizing linear workflow and your results are good support for that. Keep up the good work.

Thanks a lot. Regarding LuxRender I am struggling at the moment with quite basic problems. I must resolve them in the luxrender forum before I can go on.

I think you are quite right here. I had a look at some real photographs and their histograms. What always troubled me with my current render, was that I ended up with the histogram shifted too much to darker tones resulting even in black spots after convering to 8 bit. Just playing with the curves didn’t do the trick, so I will have to adjust the ambient lighting.

In my current setup I already use the gamma node. Much easier to handle.

Oh, I have to thank you in this case. It all started when I stumbled upon your excellent tutorial on this issue a couple of months ago. But I had to go through some pain before recognizing the inherent logic and thus benefit of working with a linear workflow. And as I am doing quite a lot of RAW digital photography these two areas now fit much better together.