Frequently Asked Questions: Technical

Transcription

1 Frequently Asked Questions: Technical Importing and exporting geometry Which file formats are supported by Maxwell Render? The file formats supported by Maxwell Render are MXS, OBJ, STL, LWO, NFF, XC2, DXF, 3DS, XML, FBX, PLY and DAE (Collada). I am getting the following error message: Current geometry is protected and cannot be exported. This is a fairly common warning when you are trying to export an object in an MXS file to an OBJ file in Maxwell Studio. This was made to protect the authorship of models. Within the plug-ins, when exporting to MXS you can choose to protect the geometry (thus not allowing it to be exported as an OBJ). All the old MXS files are protected by default. Can I render my old MSX files that I saved in Maxwell Render version 1.x? Can I render the new MXS files I have created in Maxwell Render version 2 with Maxwell Render version 1.x? Maxwell Render 2 will allow you to render your old MXS files created in Maxwell Render version1.x. However, the new MXS format includes much more information about the objects, scene and materials than those created in version 1.x, so the scenes created with Maxwell Render version 2 won't be readable in your old Maxwell Render version 1.x. Common errors in rendering Some polygons render black. What should I do? - Make sure your geometry does not have any coplanar polygons that share the same space. - After importing your geometry into Maxwell Studio you might want to select the object and press "Recalc normals" in the Object Parameters panel to remove any possible normal errors. - Check that your object doesn't have any reversed normals by checking the "show normals" checkbox in the Object Parameters panel. Fix any reversed normals by clicking on the Reverse Normals button in the Object Parameters panel. The following error message has appeared: UVW channels (2) on object "myobject" not enough for material "mymaterial". What should I do? In Maxwell Render, UV channels (UV sets) start from 0. This means that, if an object only has one set of UVs, but you apply a material which has a texture that uses UV channel 1, this would mean the object needs to have two sets of UV channels (0 and 1). You will get this error message if the object does not have enough UV channels to render the material applied to it. If your object only has one UV channel, make sure all textures (diffuse, bump, weightmap etc.) are set to use the projector channel 0 in the Texture Picker. Environment variables I am getting the following error message: "The material preview scene cannot be found." What can I do? This error message shows up when you are trying to load Maxwell Studio without a layout. This happens because you had a previous version of Maxwell Render installed in another path and your MAXWELL2_ROOT environment variable has not been changed correctly when you installed a new version. This means that the software is still referenced to the old path. It s easy to resolve this issue. Revise the MAXWELL2_ROOT environment variable and update the path, rewriting the new installation path in the corresponding window. I am getting the following error message: "MAXWELL2_ROOT environment variable not found. What can I do? It has come to our attention that the installer is apparently having difficulty satisfying the prerequisite of finding MAXWELL2_ROOT on some installations. The installer has always required this, but it seems that the Maxwell 1.6 installer may be setting MAXWELL2_ROOT only at the User level. So, if you get an error during the installation, indicating that Maxwell Render could not be found, please edit your machine's Environment variables, adding a System Environment variable of MAXWELL2_ROOT, which points to your Maxwell Render directory, and another MAXWELL2_MATERIALS_DATABASE environment variable pointing to your material database folder (usually inside the Maxwell2 installation folder).

2 The System Environment variables are located in the lower box, as seen here: Environment variables may be accessed on XP by: - going to the Start menu - right-clicking 'My Computer' - clicking 'Properties' - going to the 'Advanced' tab - clicking 'Environment variables' They may be accessed on Vista by: - going to the Start menu - right-clicking 'Computer' - clicking 'Properties' - in the dialog box, clicking the 'Advanced System Settings' link - clicking 'Environment variables' Mac OSX How can I fix Mac OSX license issues? Check that there is only one version of Maxwell Render in the system. If there is more than one version, it

3 could cause conflicts in the license detection system. Also make sure there isn t a version of Maxwell Render in the trash can. We strongly recommend that you empty your trash can if you are having license issues. I'm trying to launch a network render in a mixed (PC/ Mac) network and it keeps failing. What can I do? You should have all the files necessary for the render in a Windows shared folder on your PC, as Mac can handle Windows network paths automatically, but not vice versa. Where can I put my files to do a network render in Mac OSX? All the files for a network render must be located in you user folder (or any of its subfolders) or in any secondary drive. It's also very important to do a "Pack & Go" in Maxwell Studio, to be sure that all the files can be accessed easily from all the machines. When I try to render, Maxwell Render gives the following error even when I have no additional instances of Maxwell Render open and am not working in network: ERROR: Maximum number of licenses reached. Render cannot continue. Deselect all the network ports you are not using on the computers and try again. You can do this in System Preferences/ Network. Leave only those that you are currently using activated Instances Does Resuming work with instances? Resuming does work with instances; you just need to reload MXS and select Resume before you hit Render again. Avoid stopping and resuming in the same session to stop instances gradually disappearing. When I enable Motion Blur I don't get instances, I get copies. Motion Blur and Instances cannot currently run together in Maxwell Render. So if Motion Blur is enabled in Maxwell Render Options, the plug-in will automatically treat instances/copies as standard geometry, allowing the render to show the desired motion blur (but not giving the same benefit to the memory as instances). Materials/ Texturing/ Rendering Will my old materials be compatible with Maxwell Render 2? The improvements in the Maxwell Render version 2 material system allow you to create better, more complex, and faster materials. Version 1.x materials are compatible with version 2, but a small number of version 1.x materials (and therefore scenes) may not look entirely correct. We recommend to re-do as many version 1.x materials in version 2 as possible to make them into materials of a far superior quality. The only materials that can present difficulties are SSS materials and Clipmap materials. My old SSS materials look different now. What should I do? The new SSS system is better integrated into the general BSDF structure, making it more intuitive and easier to configure. As the new SSS model is slightly different to the old one, your old SSS materials might appear slightly different when rendered in the new version. To get them to look the same again, you will have to raise your Scattering Coefficient to a much higher value. My old Clipmap materials look different now. What should I do? The new stacked layer system allows you to create more complex materials in a more intuitive way. Previously, you had to play with transmittance maps to get a simple Clipmap. Now, to create a Clipmap material, simply set up your material as usual, and apply the Clipmap in the Opacity/Mask map in the Layer Properties panel. My glass objects come out black. What should I do? Check your transmittance color and attenuation distance. The attenuation distance should be around 3cm for common glass and about 40cm for high grade glass. You must also check your scene scale. Finally, make sure your transmittance color is set to anything other than pure black (0,0,0). Why aren t the Arroway textures included in the installation? The Arroway collection of materials and textures were always available since the early versions of Maxwell. For this new version, clients asked us to make sure the installation pack was lighter so they could download it faster, so we decided to remove the Arroway collection and a number of other textures. Of course, the collection is still available for clients on our website.

4 However, we did leave one Arroway texture in the installation file so you can test it the first wood material, named "boards-01". You can download the whole material collection from our website, under "Additional Contents". In the Material Editor, what does the K parameter mean? What is the difference with the Nd parameter? From a physical point of view, the index of refraction is not just a plain number; it is derived from a complex calculation to define the refractive index at one particular wavelength. This is the calculation: Refraction at a particular wavelength = Nd + K.i The Nd represents the refractive index, which is the well-know concept of Index of Refraction we often use. The K is the extinction coefficient: the amount of absorption loss when an electromagnetic wave propagates through a material. This is usually confused with the Abbe, but it is not in fact related to this. K is related to the extinction of the wave. The use of the K value is optional. In most situations it is enough to just use the Nd value. It is only necessary to use the K parameter to get a more precise result in specific situations where the extinction effect is important. The values of the extinction coefficients are obtained from measurements in laboratories, and are also included in the IOR files. Where can I set an.r2 file to be applied to a material? The.r2 files (which controlled the falloff between the color at 01 and 90º) have now been replaced by the r2 numerical boxes, where you can directly introduce the two values included in the.r2 file. The result is the same, but the use is now more straightforward. Lighting/ Multilight My render comes out black, even though I've added emitter materials. Maxwell Emitters behave according to real-world parameters. Therefore, it is necessary to: First of all, check the scale of your scene (which you can do by importing your MXS file into Maxwell Studio). As Maxwell Render is a light simulator, scene scale is very important - you cannot illuminate a 2 km2 area with a 60 Watt light bulb. Check the normals of your emitter objects. You can try reversing them with the "Reverse" normals button in the Object Parameters panel, and then rendering again. Check your camera settings, particularly the f-stop, Shutter speed and ISO parameters. If there is not enough light coming into the camera, the image will be black. Make sure that the Emitter power is defined correctly. (Don't forget efficacy for watt-based emitters.) Will the new Multilight Color + Intensity mode render slower than the classic Multilight Intensity mode? No. The new Multilight Color + Intensity mode stores not only the intensity information of each emitter separately, but also the spectral color information of each separately, to allow you adjust each emitter to get full control over the resulting image. The process now will consume extra memory (as the spectral contribution of each emitter is stored is a separate buffer, which needs more memory per emitter in the scene) but it won't affect the render speed. Why don t emitters defined by Color Temperature have a color chip in Multilight to change their emitting color? With emitters defined by Color Temperature, the emission color is tied to the intensity of the light, just like in real light sources. Therefore, when you lower the light intensity, you not only get a dimmer light, but also a red color, according to the Kelvin scale. By raising the light intensity, you not only get a brighter light, but also a bluer emission. This is only for emitters defined by Color Temperature. In Custom emitters, you control the intensity and color of the light separately. Why doesn t the Physical Sky have a color chip in Multilight to change their emitting color? The color of the Physical Sky light is not editable with a color picker. Its color depends on the sun temperature, atmospheric conditions and location and time in the scene. Changing it with a random Color Picker would impair the light correctness of the Physical Sky light.

5 Rendering speed and performance How much faster is Maxwell Render version 2 compared to Maxwell Render version 1? There is no one answer to this question. For Maxwell Render 2 we completely re-designed the render engine from scratch, making it much faster and fixing a great many internal bugs. We've also included several optimizations for a number of specific situations. So there will be scenes that will render 2 or 3 times faster than in Maxwell Render version 1. In other scenes you will see results that are 5 or 6 times faster. Another scene will show an even higher speed improvement. It depends highly on the scene and varies from one situation to another. There is no specific, set speed improvement value in Maxwell Render 2 in comparison to Maxwell Render 1. Can I compare the Benchmarking values or Sampling Level values between Maxwell Render 1 and Maxwell Render 2 to compare the performance of the new version? No. The Sampling Level and Benchmark values are performance ratios that depend on the calculation algorithms. For Maxwell Render 2 we redesigned the rendering algorithms inside the engine, so the new Sampling Level or Benchmarking values are only useful for comparing Maxwell Render 2 scenes. Given that the same SL value gives you a much higher quality and cleaner render in Maxwell Render 2 than in Maxwell Render, it makes no technical sense to compare the values from two different engines. The only useful parameters for comparison between Maxwell Render1 vs. Maxwell Render 2 are time and image noise, which are obviously non-algorithm dependent values. My image is extremely noisy even after a long render time. What should I do? There are several things you can do to optimize a scene, mostly related to emitters: - Make sure your emitting surfaces are as low-poly as possible. Usually, a single-sided polygon will be sufficient. - If possible, do not completely enclose your emitters inside a dielectric object. - Make sure your emitter is not intersecting other geometry. - Very important: do not include very white or fully saturated materials in your scene. For example, a completely white (255, 255, 255) material will take a very long time to clear and will also make the contrast in the image disappear. Also avoid completely saturated colors such as pure red (255, 0, 0). Pure white or pure saturated materials do not exist in real life so it's better to decrease the saturation a bit. For a white wall, around RGB 220 or less is sufficient. - For interior renders where window glass reflections are necessary, use the AGS glass material for the windows instead of real glass. This will create the reflections but will not produce any caustics, thus speeding up the rendering. - Perhaps you simply need more time for rendering, depending on your machine specs. Check to find out how fast your machine is. Where is the RS0 preview render in Maxwell Studio? For Maxwell Render 1, it was useful to have a faster preview render engine to get a quick preview of the final result. Now, we ve improved the rendering speed so much that the Maxwell Render 2 core engine is even faster than the old RS0 preview engine, so it no longer makes sense to include it. Hardware How can I increase the use of RAM per application? Some processes in Maxwell Render require the use of a lot of RAM. Windows 32bits use up to 1.6 GB per application by default, but you can increase this up to 3GB if you edit the boot.ini file. You can change this by doing the following: -Press RMB > Properties in Start > My Computer. -Go to Advanced Tab > Start and Recovery > Settings. -Press Edit in System Startup section. -Go to a line that contain something like multi(0)disk(0)rdisk(0)partition(1)... and add at the end /3GB. -Save the file and reboot.

6 Which computer should I buy to take full advantage of Maxwell Render? We always recommend using powerful, fast processors because this will have a major impact on render times. Moreover, when you are dealing with big scenes, you will need large quantities of RAM. Take a look at to see speed comparisons for different machine specifications. Can my graphics card make my renders faster? The graphics card is not involved in the rendering process. The graphics card is only important when you are setting up the scene in the OpenGL viewport (in Studio). A better graphics card will allow you to move more geometry and textures faster, but it is not involved in the rendering process. The component that controls the rendering calculations is the processor. Using either a faster processor (GHz), a multi-core processor, or several CPUs in a farm, is the best ways to reduce render times. What are the minimum system requirements for Maxwell Render? The minimum system requirements for Maxwell Render are as follows: Windows (32 and 64) Windows XP, Windows Vista, or Windows Server GHz Intel Pentium 4 processor, AMD Athlon 64 or better 1GB RAM minimum. 4 GB of RAM memory is highly recommended 400 MB available hard disk space for installation Accelerated OpenGL drivers 3 button mouse recommended Linux 64 x86_64 distribution with a 2.6 Kernel and glibc GHz Intel Core 2, AMD Athlon 64 or better 1 GB RAM minimum. 4 GB of RAM memory is highly recommended X server with accelerated OpenGL drivers 300 MB available hard disk space for installation 3 button mouse recommended Macintosh (32 and 64) Mac OSX 10.5 and up PPC or Intel CPU. Intel is strongly recommended 1 GB RAM minimum. 4 GB of RAM memory is highly recommended 400 MB available hard disk space for installation 3 button mouse recommended * PPC systems only allow Maxwell 32Bits Networking How can I set up my network to get an optimal performance for network rendering? - Make sure that all the machines in the network have the same version of Maxwell Render installed. Many transference problems in the network are caused by having different Maxwell Render versions all over the network. Updating to the last version on all machines will ensure the best communication between nodes. - Make sure that all the nodes have the same network card or cards with similar transfer capabilities. This will ensure a good transfer speed between all nodes. We recommend gigabit network. - Keep your network as homogeneous as possible. Similar computing powers and transference ratios will make the communication between all the machines much easier. - Remember to turn off your firewall if you are getting issues detecting nodes in the network. Networking in Linux

7 How can I avoid installing an X Window on each Rendernode? Because Maxwell Render depends on an X server, it seems like overkill to install a full X window system in each render node. The solution is Xvfb. Xvfb (X virtual framebuffer) is an X server that can run on machines with no display hardware and no physical input devices. It emulates a dumb frame-buffer using virtual memory. The first step is to install it: On Debian-like distros # apt-get install xvfb Or fedora-like distros # yum install xvfb The second step is to run the server for testing: # Xvfb -shmem -screen x1024x24 This command starts a virtual X server with virtual display :0 which has virtual resolution of and 24 bit virtual colors. To test it you can run a following command: # DISPLAY=:0 xdpyinfo If everything works fine, you ll get lots of status information about your server. In the previous command, DISPLAY=:0 specifies which X display information is wanted. This variable can be exported once and then run any commands which require X server to be running. To make this virtual server run all the time and restart in case of any problems use linux /etc/inittab file. Add the following line to this file: xvfb:2:respawn:/usr/bin/xvfb :0 -ac -screen x1536x24 and reload it with init q command. It is highly recommended that the Manager and Monitor run in the same CPU. This will avoid many transfer problems.