From: Walter Rocchia (
Date: Thu Sep 19 2019 - 08:39:00 CDT

Dear Luciano,
Thanks for your reply. Probably is is possible to add color information via HTML, but rather unpractical.

In addition, I do believe there is something more than this. My impression is that color is treated differently when the surface is colored using colorID or "color by volume ".
For instance, I also tried to save a movie with VMD movie maker of a rotation around y-axis and rendering with TachyonL Optix. The .ppm files that I get represent the surface without color information.
So I have the impression that color information is not linked to vertices like it occurs with other coloring ways.

Does anybody have any clue?

Walter Rocchia, PhD, Head
Computational mOdelling of NanosCalE and bioPhysical sysTems - CONCEPT Lab <>
 Via Melen – 83, B Block, 16152 - Genova, Italy
Phone: +39 010 2897418

On 19/09/2019, 09:37, "Luciano Abriata" <> wrote:

    Ciao Walter,
    I've been using obj+mtl files for some AR applications and indeed, the colour information of some objects, particularly meshes, is lost. Luckily, in HTML you can color-code the mesh ad hoc (this only works if you don't load the mtl file, thus leaving all materials free to be set from code). Maybe you can use a similar trick in the program you are using.
    Note I have also seen some inversions going on in the meshes (like say x coordinates become -x) that I don't understand, but luckily HTML provides a way to re-invert them. I asked about these issues in this mailing list but apparently there's not much development going on.
    De: [] en nombre de Walter Rocchia []
    Enviado: miércoles, 18 de septiembre de 2019 23:10
    Asunto: vmd-l: exporting 3D model of a volume-based colored mesh
    I would like to export the mesh of a surface created in VMD and colored based on a electrostatic potential. The final aim would be to have a 3D model on it (e.g. a .u3d format)
    I tried most of the output options provided by VMD, including wavefront .obj and .mtl files. When the surface is colored with a colorID, it seems to work.
    In contrast, when I loaded these files in Meshlab, it seemed that the information of the color was missing?
    Is there any way to do it correctly?
    Thank you
    Walter Rocchia, PhD, Head
    Computational mOdelling of NanosCalE and bioPhysical sysTems - CONCEPT Lab<>
     Via Melen – 83, B Block, 16152 - Genova, Italy
    Phone: +39 010 2897418