It can be accessed by defining a luxrender texture type as a normal map in the luxblend25 exporter. Once defined like this, it is used in the  bump map slot and… bam… awesome happens.

What does this mean? Well as far as I understand, a normal map is used in a similar way as a bump map and give the appearence of a highly structured surface that is intact flat or low poly. So you might ask… so what is different?

The best way I think I can understand it in terms of lux is that, a bump map represents a height field, and lux determines the normal of the surface based on that. However, the normal map, gives the normal as a colour vector. So in a round about way, they are identical but from different starting points. Normal maps are also relative in height, rather than absolute, this  changes how you manipulate them in lux. Typically you bake the depth into the map, and set the height to 1, the height cannot be set any higher than that, though can be reduced if needed.

The other nice thing is that it is handled by the bump map code and such, makes it possible to apply both a bump map and a normal map to an object via a mix texture in the way you would expect, where the normal map is relative and the bump map is absolute.

However from my own experience playing with normal maps and lux, normal maps appear to give an altogether more appealing appearance, and are a little easier to manipulate than bump maps. This i think is more to do with image manipulation when generating the normal map, over that of forming a height map. This is possibly due to the heavy use of Normal maps in game engines, and so the software is setup to produce the results you want as normal maps, more than displacement maps.

I made a simple scene with two cubes, both are uv unwrapped and have a simple cloud texture, with a luxrender logo set on a white boarder. Here i want the luxrender logo to be raised on a flat panel, and then the text stamped into the cube.

The first thing you will notice is the softness of the normal map, and yet, it still achieve a good effect of depth, (right). The bump mapped cube is a lot rougher and doesn’t quite give the same effect of depth. Again, I think this is more to do with generating the normal map than anything else.

Here i used GIMP to make the height map texture, and then CrazyBump to make the Normal map.

In this next example, both cubes have normal maps with exactly the same properties, however, in this case, generated by GIMP with a hight of 10. You can see a big big difference, and goes to prove what i said that the difference in the two is most likely image manipulation over actual different treatment in lux.

Here we still have a smooth surface, and the logo is far less pronounced.

Running the same map at a hight of 30 in GIMP gives me this,

As expected, the surface is rougher, and the height of the luxrender logo is all together deeper.

The next example is the same map as above, put into Crazy bump with some settings changed, it is by doing this text that i see that CrazyBump likes to produce rather blurry normal maps with exaggerated depth. This isn’t totally a bad thing, it all depends what you want to do.
Here is the result,
 The most obvious part of this is that the luxrender logo is more visible, but is softer.

Next – i did some blurring and re-toning in GIMP, I can’t give instructions exactly how i did this as it did just involve two layers and a bit of blurring, simple as that. I then used the 9×9 filter in GIMP and generated a normal map,

The nice thing here is that the text and logo are well defined, and the map isn’t too sharp, it I might have got it just how i want it… however it is still a little too intense, so lets reduce the normal map hight a little bit in luxblend.

Looks good.

I think in the end it is all about playing with the tools to make them do what you want, there is no magic combination, however still think using normal maps rather than bump maps is a very powerful tool and a welcome addition to the features

The ground was produced by manipulating a high resolution plasma map generated in GIMP using crazy bump. As you can see, close up, it looks fairly poor, however at distance it looks quite impressive. Once again, i have NEVER achieved this kind of effect using a bump map. Maybe this is my own poor ability at generating height maps, either way its nice to see the enhancements

To do this I took an old scene file of mine, the spider scene I think I have posted here before.

Here is a reminder

Lets start out with the table. In the above, I also used an image map for lighting, but I have replaced the main light sources with two light planes. Not shown below is the glass, which doesnt change at all. It is simply glass2

So far so boring, I set the table to glossy, and made the diffuse colour 0.26 across the board, and the specular colour I set the texture 0.24 across the board. u and v roughness are both set to 0.05.

Lets add some texture, for the original scene i used a texture from the indigo material database. It is the Elm wood texture. in blender 2.58 i recommend splitting the material pannel in half so you can see the textures, and material settings next to each other.

To explain the panel a little, first look at the material panel. It is exactly the same almost as 2.49b.  to define the Diffuse colour to have a texture i have pressed the T button… The nice thing about LuxBlend25 is that, I have to make my textures in the texture panel before i can assign them, once it is defined, when pressing T, a box appears with the name of all the textures defined for that material.

So look at the Texture panel, Tex.001 is my diffuse colour, it is defined as a blender type image map. The ElmWood texture is set as the file name, and i have defined it to be UV mapped and scaled down 5 times. This is because, usually the textures are high res, but not a high res scan of a whole table!

NB, when defining textures, you can use the blender Texture -or- the LuxRender Type texture, for image maps they are equivalent i think. As you can see, I have set the texture to the Diffuse colour and checked the M button, which means Lux should multiply the colour of the texture by the colour defined (in this case 0.26) so it will appear dull.

Great, looks ok

I cannot remember if the packed texture contains a bump map or specular map, so if it doesn’t, i think i likely grey scaled and played with the diffuse map. Either way, I did the same for the specular map as i did with the glossy.

Here you can just start to see the difference made by the specular map in the reflection on the surface.

The fun part now is the bump map. On the original scene I only used the grey version of the elm wood texture and set an appropriate scale which gives the slight bump you see in the above.

For this, i tried to do something extra… a scratch texture too to give me a table that looks like it has seen some action, like you might get in a pub. Doing this is simple in either 2.49 or 2.58, but i found the interface to be much more user friendly and simple, allowing me to define a few textures and have them all to play with, rather than a HUGE long vertical list like it would be in 2.49, where each texture has to be defined by hand. Here things are defined and then put into slots, the system is wonderful.

I googled before for a scratch texture, once more, i cant give the address to go and get it because i cannot remember, sorry. So i defined the scratch texture in the same way as I did the glossy and diffuse. I then used a mix texture to give me a 50:50 merge of the scratch texture, and the Glossy texture. This time i didnt NOT press the M button on the textures, As i didnt want to weight them.

For this scene the approximate scale height for the bump map as you can see from the above panel is 0.0004, (0.4mm), I put the mix texture into the bump map slot and selected the M, so the texture height is scaled appropriately. I think this could be a little too high a scale for the bump map when looking back at the original image.

Either way – the final image, along with the spider, and another spider + beer mat is as follows.

The colours look a luttle different, mainly due to tonemapping. However, the extra experience I have had with material setup between the original and now shows a little. I am very happy with the table and will likely feature it more often.

This is the final result, sorry for not including more pictures of panels, much of it is i believe self explanatory from the images shown, and the text. I found that once i got started and defined a few textures, everything actually fell into place.

My only word of caution is that, it often appears like textures do not work when you hit preview… if this happens, it usually means you have mixed up a float texture with a colour. A float texture is when a numerical value is given as the texture, such as in a luxrender procedural map. The best solution to this is to do a mix texture… a two step texture where you define the colour in the mixed textures, and the mix amount to be the procedural texture. Getting this right and getting it into your head in the right way is a bit difficult. I have had a few occasions where textures seem not to work at all…

This problem was taken care of in LuxBlend2.49, so it is something that was hidden to the user. I am not sure if there are plans to change this for LuxBlend25, but it isn’t too bad once you understand the differences.

Bump maps for example tend to cause most heart ache for this… but… from advice, bump maps should be grey scale or floats in general… and things will be ok.

The Error was this
ImportError was: /usr/local/lib/libboost_python.so.1.43.0: undefined symbol: PyUnicodeUCS2_AsUTF8String)

I was helped alot by a member in the luxrender IRC channel, (THANKS ONCE AGAIN! Orbisvicis) and would like to share what we think was the problem and the fix. For my records and for anyone who is unlucky enough to see the same error. I say unlucky because from experience, getting and compiling boost and having it link with everything, can be extremely painful. I lost count of the number of times i compiled python boost and luxrender yesterday.

OK so it appears to be a unicode problem, the exact cause could be a number of things

• unicode support was not included with the python I compiled.
• pylux is linked against an incorrect version of python.
• the python implemented/packaged with blender is causing the issue.

The easist one of these to check is the linking in pylux.so use ldd pylux.so to check the library dependancies. Look for things that look odd or out of place. NOW this is were I had my problem. Despite Boost being built against the correct version of Python, when make finally linked pylux.so, it fell back to my systems pre-installed Python2.6… so it was getting confused by this.

HOWEVER for completeness I will detail the final full solution of building python correct for the job and luxrender.

First i got the latest version of python 3.2.1rc1
http://www.python.org/download/releases/3.2.1/
I applied a patch to the python, for the boost libraries

Python was then built with the following command.

./configure –prefix=/usr –enable-shared –with-threads –with-computed-gotos –enable-ipv6 –with-valgrind –with-wide-unicode –with-system-expat –with-system-ffi; make

I changed –prefix to my desired build location. and did a make install after the above command. NB you might get an error during the compile, however, these shouldnt be anything you need (for LuxBlend or LuxRender) if you need to fix them, unfortunately that will be up to you, sorry.

I also got a later version of boost, 1.46, however the build process is IDENTICAL to that talked about previously however, be sure to check you used the correct include directories, as the normal
/……./python32_build
/……./python32_build/include/python3.2m
directory will have a ‘u’ on the end (signifying unicode?)
/……./python32_build/include/python3.2mu

Boost should (at least it did on mine) compile perfectly fine.

The next part is LuxRender. The part here is cmake will often default to system directories in case of issues, and unfortunately this causes alot of issues. Cmake in luxrender was reorganised recently, and is likely still undergoing some change. there is a directory, cmake in the head directory of lux which contains a few useful files in which you can change cmake include directories and search paths.

in my case because python was likely my issue when i did the cmake i used the following commands

-DPYTHON_INCLUDE_DIR=<link to include dir>
-DPYTHON_LIBRARY=<link to actual lib file>

A full list of all options can be found in the CMakeCache.txt file which cmake generates… there are MANY MANY MANY and with the new cmake rewrite, if you have problems you can write your own custom config file and load it. Once you have picked out the ones you need you can use them by

cmake -DPYTHON_LIBRARY=<link to actual lib file> .
for example.

I was able to use blender with pylux.so and all was right with the world.

Once again thanks to the help i was given in IRC, and I hope these notes can come in handy to anyone suffering similar issues. Even if the error isnt exactly the same as shown here, the cmake notes at the end can fix so many issues. Also for library problems ldd is your friend.

However I did enter the Simple is Beautiful competition. Long ago I attended a conference and during the tea/coffee bio break session there was a technology stand, it was quite striking and showed what appeared to be the fuel/control rods at the top of a reactor, surrounded in a bath of Cherenkov blue haze. It was very pretty, and since then i thought about making something similar in Lux.

However, back then to achieve such and effect was possible, however it was somewhat limited and involved using the Bound Volume interface, I never got it to work in a satisfactory way. With the advent of homogeneous volumes in lux, it became possible to do this far more easily, and quickly.

I cannot go into alot of detail, as the scene is infact very simple. It consists of a long tube, which is filled with smaller tubes of a similar length. The inner tubes are smaller and are supposed to represent the control/fuel rods. I then used the homogeneous volume settings to set the atmosphere to absorb and give me a blue haze, and the scattering value to something small, but large enough to give me a desired brightness for my ‘god rays’.

Physically this isn’t really correct, as the Cherenkov is an emission rather than a scattering, and the blue colour isnt from the absorption at all… however, to fake the effect I was after, for this scene it is ok.

The part which really gives the cross lighting effect in my scene is that the lighting is a disc placed at the bottom of the larger tube, it is small and only really covers the inner 4 tubes, hence any other light that is seen is an effect of scattering or multiple bounces around the scene.

The scene was rendered for about 1 week on 6 CPUs and here is the result.

I decided that I would switch over to just having Windows 7 and Linux, as I haven’t used XP in a long time. I would also change distributions of Linux away from Ubuntu to… Scientific Linux.

What? Why? What the Hell is that?

Scientific Linux was the first linux I was introduced to during my PhD, back in those days (despite it being only 5 years ago) SL 3 was on the systems at Uni, and, while functional it was pretty terrible and getting anything to work was extremely hard work, getting the correct versions of everything was a big task. SL is maintained mainly by the particle physics community, and such it is loaded with useful things as a development environment pre-shipped, however like I said above, it was a little behind the pace back in those days.

Things are a bit better now with SL6 and in the whole is more up to date and compatible
with hardware.

I have collected together all the helpful and handy hints I used after SL was installed in order to get LuxRender built, along with useful things like… graphics drivers.

Graphics Drivers (Nvidia) The original is instructions are listed here but I present a shortened version

1. Get the required dependancies : yum install kernel-devel gcc
2. Grab the Nvidia Driver of your choice
3. black list the nouveau driver
   edit : /etc/modprobe.d/blacklist.conf
   Add : blacklist nouveau at the end
   black list in grub by editing, : /boot/grub/menu.lst
   Add : rdblacklist=nouveau at the end of the line starting with kernal, of the one you want to install the drivers
4. Set the default init level to 3 to stop the graphics drivers being loaded during start up
   Edit : /etc/inittab
   Replace id:5:initdefault: with id:3:initdefault:
5. Reboot
6. log in as normal and run the nVidia installer
7. Reboot
8. log in again, and type init 5
   If everything went well, the GUI will load and everything will work perfectly
9. If all is good, reverse point number 4.
10. If all is bad… follow all this backwards

My experience with this isnt great, so i take no responsibility if you brick your linux… I certainly have tried to cut corners in the past and ended up in a total mess. These instructions i followed to the letter and successfully installed a v275 series driver in Scientific Linux 6_x86_64.

Building LuxRender

I used a guide posted on the LuxForum  If you follow it to the word, everything should work fine. You can use yum or apt-get in general to install all the dependancies you need and in the case of boost and python, follow things to the letter of the guide and you should not get any problems.

Notes :

If you have installed the nVidia drivers, you will usually have OpenCL and Cuda libraries installed in your system, and thus not require the ATI Stream SDK as listed in the guide. HOWEVER you will need to make a /usr/include/CL folder and copy the OpenCL headers in there. This can be taken from the ATI Stream SDK or, from the khronos group page.

The only things i changed was that i didnt use the ATI stream SDK as explained. I also copied the compiled boost libraies to my system and removed version 1.41 which shipped with my system.  Other than those  you might need to get hold of is libGLEW and compile and install which isn’t really listed as an instruction.

With a little discussion and following that guide i was able to get LuxRays and LuxRender built and running on Scientific linux… which was a nice moment.

I cant really complain since in this respect blender isnt really performing an animation, it is the game engine. I finally found a way to remove animation information, but it is somewhat tedeaous and im sure there is  a better way. All you do is go to the Dropesheet and select the object, and delete the position and rotation channels. For the most part this esensially clears all the information. For my scene it didnt reset the position or rotation but left the object where it was on that frame. I should experiment more, but for my cleanup it worked out just fine.

In order to make my background a little more interesting i added a second set of mountains/hills by instancing the original background and pushing it back a little, and rotating. I experimented adding a few rocks, this looks reasonable, however I think i need to remove the texture from them as they look like sandy blobs rather than rocks.

I also used arch glass rather than the full glass refraction, this was an experiemnt to speed up the render time. I also changed the volume integrator to single over multi, and in effect boosted my render speed, from about 500S/s to 10kS/s which is nice. I had to increase the scattering scale however to get a scene similar to what i had before.

Here is the result.

I have some kind of grid artefact in the sky, likely caused by numerical accuracy, but i will be checking with the people at Lux to see if anything obvious can cause this.

I spent some time modelling a helmet, this was a challenge for me but rewarding none the less,

One helmet, as you can see i placed the camera inside it, the focal length of an eye is somewhere between 17 and 24mm however for a camera this doesnt appear to give the same sense of peripheral vision. So i made it shorter to get more of the scene in.

The next part is working out the reflections for the inside. Now i did a number of test renders with glass and the number of reflections where minimal, this is good you might say, as a helmet would hope to reduce the number of reflections as not to confuse the user. And you would be right… however, to have zero reflections is also not in my opinion realistic and takes away from the fact it is an inside helmet view.

I thus added a mix material of glass2 and a 1%mirror and tested that. I also placed a mesh face inside the helmet. As you can see the face is placed far far far behind and not exactly where the real viewing place would be. again, this will need some moving and adjusting.

The last thing i tried was to make a HUD, in order to have some kind of computer overlay to the scene, im not sure i like this but will at least keep it there for the time being.

The last point to make is the volumetrics,

I initially had problems that the volumetrics would be reset when the light passes through the glass of the helmet… that is, the scattering simply would not be there and it would be perfect daylight outside. It appears that if a volume is planar and thin, then this can happen for a scene like this because of rounding errors and the step size of the volume. In total i had to use a thickness of 0.04 using the blender solidify tool, which is somewhat unphysical, but i will look at that later.

Here is the resulting 10hr render

As you can see i dint play around with all the materials this time, because im in blender 2.57 i have to rework all the materials. I think i need to raise the scattering a little bit, but other all, it isnt too bad a progression. The soil needs better detailing i think, probably a displacement map or higher bump map.

To get hold of it, along with the exporter of your choice, click this link

A number of things have been changed since 0.7.1 a few of which are listed below

• New GUI options for saving tonemapped images
• render queues
• new lightgroup handling, and GUI options
• Glossy Translucent material
• Band texture for complex gradients
• Volume scattering (homogeneous)
• ply mesh loader
• on the fly microdisplacement subdivision

The full list is rather long, but these are the ones that spring to mind as the major features as a user.

I am moving over to Blender2.57 and such the scene has slowed down a little once more as i try and match the luxblend settings.

One thing that I always found difficult to create was a truly different or strange environment and make it look like i didnt just do something strange with the tone mapping.

I loaded up an old version of the scene and applied minimum settings for volumetric scattering. Here is the result.

The number of samples here is fairly low so it is very noisy, but despite that, the scattering gives a impressive glow from the sun and the sunsky. It also gives a slight perception of depth as the hill fades to the left of the scene.

Since then I decided the following

1) Make my own Environment exactly how i want it and to the scale i want it. The specs of this are approximately the following;

Scale -> about 2km square
Environement -> A long trench drawn out be the ship/object, surface should be sandy with rocks and debris scattered.

I spent a little time trying to create this world, and imported the starship part. Once more i applied minimal settings for the scattering volume and hit go.

One thing that always bothered me in my previous work with this type of scene is that ultimately the scene will be from someone looking out. So I used a cube as a setting device. The camera is located 1.7m above the ground, with the cube being 1m in dimensions set a short distance ahead so it is visible.

It is a start