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Sim4Life

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  • Installing Sim4Life and configuring licenses

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    37 Topics
    128 Posts
    M
    Hi, yes, we have new agent in China and the contact email is zmt_china@163.com.

  • Working with CAD models

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    227 Posts
    S
    Hi everyone, I am experiencing several rendering issues with the Sim4Life 3D Viewer when running Sim4Life on a Windows server through Remote Desktop (RDP). Colors change when selecting an individual model element. When I select the Model folder in the Explorer, all elements are displayed correctly: [image: 1786565631056-screenshot-2026-08-12-161301-resized.png] However, as soon as I select an individual element within the folder, the colors of the model change significantly and no longer correspond to their normal appearance: [image: 1786565696244-screenshot-2026-08-12-161442-resized.png] Elements disappear when opacity is below 100%. If I change the opacity of any element to a value below 100%, the element completely disappears from the 3D Viewer. At the same time, the colors of the remaining model are also altered, even when I select the entire Model folder again: [image: 1786566049952-screenshot-2026-08-12-162026-resized.png] [image: 1786566083849-screenshot-2026-08-12-162105-resized.png] The server has the following specifications: OS: Windows Server 2019 Standard, version 1809, build 17763.8755 CPU: Intel Xeon Platinum 8160 @ 2.10 GHz RAM: 1.50 TB System: 64-bit OS, x64-based processor GPUs: NVIDIA Quadro P1000, NVIDIA Tesla V100-PCIE-32GB NVIDIA driver/OpenGL information: Initialized OpenGL view 4.6.0 NVIDIA 539.64 [Quadro P1000/PCIe/SSE2], backwards compatible, 8 multi-samples Connection: Windows Remote Desktop (RDP) Sim4Life version: 9.4.2.21604 The 3D Viewer itself initializes successfully, but these rendering problems persist. Does anyone know what could be causing this or how to fix it? Thanks!

  • Working with models from the Virtual Population

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    63 Topics
    288 Posts
    J
    Good evening. Please, I want to ask if there is a model or phantom that contains the lower limb tibial nerve. Best regards,

  • FDTD, Low-Frequency, Neuron, Mode-Matching, Flow, Acoustics, etc...

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    V
    Hello, I am setting up an LF Electro Ohmic Quasi-Static simulation using the DUKE_POSABLE 3.2 model. I have placed two solid spherical electrodes in contact with the body and applied Dirichlet boundary conditions. After voxelisation, the electrodes appear hollow or lattice-like, as shown in the attached screenshots, even though the original geometries are solid. I used a local 1 mm grid for the electrodes, while the anatomical model has a maximum grid step of 2 mm. Could you please explain what may be causing this appearance? Is it only a visualisation effect, or does it mean that the electrode interiors have not been filled with voxels? If the electrodes are actually voxelised as hollow structures, could this affect the electrical contact with the tissue, including the calculated current distribution or contact impedance? Also, is there a way to check whether the electrode material has been correctly assigned throughout the entire electrode volume? Thank you. Here is the screenshort of the voxel: [image: 1789648394768-screenshot-2026-09-17-104009.png] Screenshort on simulation settings: [image: 1789648532529-screenshot-2026-09-17-104234.png]

  • Postprocessing results

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    126 Topics
    383 Posts
    Z
    Hello, I am having an issue when evaluating SAR results in Sim4Life. When I try to view the SAR result (e.g., psSAR IEEE/IEC 62704-1 Avg.SAR(x,y,z,f0)) over the original simulation domain, Sim4Life reports an error indicating that the grid is too coarse, and I cannot obtain the SAR result. However, if I first use Crop to reduce the analysis region to a smaller area around the region of interest, the SAR evaluation works and I can successfully visualize the SAR distribution. The underlying simulation results and grid remain unchanged; I am only changing the spatial region used for post-processing. Could you please clarify why cropping the analysis region changes whether the SAR evaluator considers the grid sufficiently fine? In particular: Could a coarse-grid region somewhere outside my region of interest cause the SAR evaluation for the whole domain to fail? If the SAR result becomes available after cropping out those regions, can the SAR values within the cropped region be considered valid, or should I refine the simulation grid and rerun the simulation? Thank you for your help.

  • Scripting interface for Sim4Life

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    144 Topics
    449 Posts
    R
    thanks Robin!

  • Running Sim4Life over a network

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    4 Topics
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    ofliO
    Hi, Please allow me to share here the response we sent you via the Sim4Life support email so that other users can benefit from your questions. The default machine provides 500GB of storage, and you are running out of space for this project. If your results require more than 500GB, consider upgrading to a higher-tier machine with greater storage capacity. Alternatively, you could reduce the size of your simulation project by splitting it into multiple smaller simulations. This would allow you to continue using the default tier. Additionally, you might optimize your sensor settings, such as by creating smaller sensors and recording data for specific volumes of interest, rather than using an Overall Field sensor.
  • L

    Cannot read document verion

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    L
    I have two versions installed (6.2.2 and 7.00) and I tried opening the file with both. I have now deleted the smash file that wasn't working and started over, but if it happens again, I will try the import option- thanks!
  • V

    Bone identification using RF signals

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  • S

    The file I created with Sim4Life light cannot be opened.

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    brynB
    If you don't have a full version, i think (untested) you can still recover the model by importing the smash file in the modeling tab.
  • P

    'Point Sensor Tool' is not available

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    M
    Sorry, don't have S4L with neuron available at the moment, but I looked at the tutorial and it seems to have changed. When you create the sensor settings can you try to drag and drop the axon to the sensor setting and then chose the section name? (That was the old way of doing it) Still, you should be able to run the simulation without a point sensor.. Sorry can't help more
  • L

    Everytime I'm doing a too complex simulation the file is lost

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    L
    I am using Sim4Life 6.2.1.4972. It happened once when I've had put a high "maximum number of samples" in the time domain (200 I think) with the acoustic head tutorial that I changed a bit, by putting 2 transducers instead of 1. Another time it was weird because it happened with a SEFT targeting a square of skin, which was rather simple but it did crash again. My simulation was probably wrong in a way, but it didn't throw and error and just stopped. But now that I am applying @gbgbha advices, it is fine and thanks for the tip ! I'll try for the file that I lost
  • R

    Why does TRP exceed input power(Antenna)?

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    S
    The TRP is computed in a different way than the input power. Both ways are mathematically correct and would both be "exact" if there were no numerical errors. In any FDTD simulation, however, there are spatial (finite grid) or temporal (finite time step) discretization error. What you are seeing in this half-wave dipole example, is that those discretization errors are larger than the precision you would require to distinguish TRP from input power (because the radiation efficiency is very high in this case, there is almost no difference between TRP and input power). To solve this "problem", either you accept that the simulation results are accurate enough for your needs (the warning is a simple consistency check) or you increase the precision of the simulation. You can do so by increasing the grid resolution, the overall convergence level and the resolution of the far-field sensor. This will be computationally expensive, though. To help you understand, you could try to add some lossy media in your (coarse) simulation (e.g. place the dipole next to a phantom or any other dielectric). The simulation will not be more precise, but the numerical errors will be less "obvious" because they will be dwarfed by the losses occurring in the dielectric. The TRP will be lower than the input power and the warning will not be triggered. I hope this helps.
  • D

    The effect of electromagnetic field on the temperature of human tissues

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  • A

    S4L is unable to read and load my project

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    ali.oezenA
    THank you very much for the hints.
  • E

    How to export images from Sim4Life Analysis Results

    image export png jpeg
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    M
    That works! If it's for a 2D plot, you can always right click and export the data to an excel or csv file and then work with that if you'd prefer
  • A

    Optimal performance

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    S
    The full version has the same performance as the Light version: it can just deal with bigger problems. Note that the low-frequency solvers are not GPU-accelerated, so if you are using that the GPU is anyway not used. If you are using the FDTD solver instead, it is accelerated by the GPU but its performance might be severely affected by the frequency of your simulation (the lower the frequency, the more iteration the FDTD method has to do in order to reach convergence). If you are in a regime where the quasi-static approximations hold, I would strongly advise you to use the LF solvers.
  • J

    Editing the excitation signal

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    S
    I think your signal was fine, but your settings for the Field Sensor need to be changed.
  • J

    Invalid Bounding Box Error

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    S
    2kHz will probably not be feasible in most propagating media, because the wavelength will simply be too large compared to the grid resolution your geometry requires (leading to unreasonably large time steps). You might want to check for e.g. what your grid look like, especially the padding at the boundaries of your computational domain.
  • H

    This topic is deleted!

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  • S

    CEM43 / Arrhenius Thermal Damage

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  • S

    how to model a bent wire with a fixed length?

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    S
    Thanks for the code. Actually I need to model some wires with the fixed length, with one part in the brain in different spots and the remaining out of the brain, It takes a long time to model each one and I'm looking for a way to make them in a shorter time. Thanks.
  • S

    grid resolution of wire and insulation

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    S
    Thanks for your reply.