Depthmap creation

[Anonymous]

Hi all.

Complete novice at work here. Ok, I simply want to make greyscale depthmaps to cut on my router. My process is:

Meshroom to combine my images.

Meshlab to then use the shaders menu to create the depthmap.

Some of the 3d images though look quite rough in meshlab, even if I select the textured obj file from meshroom, for this reason I looked around and stumbled on Meshmixer. The textured image is far superior but, (and this is where my skill level drops off a cliff) After I clean up the rubbish and sliced the image I don't think that I can create a grayscale depthmap in Meshmixer - please correct me  if I'm wrong and explain how. So, what I do is: I then export the obj file so that I can do the render in Meshlab but Meshlab will not read in the texture data, the error is: Some material definitions were not found. I'm not worried about the small imperfections as I can clean those in Gimp when I get the PNG image. In the folder where the OBJ file is, there is also an MTL file and a Texture atlas_0, 1 and 2. I thought I found the answer by renaming Texture atlas_x.Png files to just Texture_0, 1 & 2 as they look identical to the ones Meshlab will read in....It did not work, maybe I'm barking up the wrong tree.  Thanks.

[Anonymous]

Hi all.

Complete novice at work here. Ok, I simply want to make greyscale depthmaps to cut on my router. My process is:

Meshroom to combine my images.

Meshlab to then use the shaders menu to create the depthmap.

Some of the 3d images though look quite rough in meshlab, even if I select the textured obj file from meshroom, for this reason I looked around and stumbled on Meshmixer. The textured image is far superior but, (and this is where my skill level drops off a cliff) After I clean up the rubbish and sliced the image I don't think that I can create a grayscale depthmap in Meshmixer - please correct me  if I'm wrong and explain how. So, what I do is: I then export the obj file so that I can do the render in Meshlab but Meshlab will not read in the texture data, the error is: Some material definitions were not found. I'm not worried about the small imperfections as I can clean those in Gimp when I get the PNG image. In the folder where the OBJ file is, there is also an MTL file and a Texture atlas_0, 1 and 2. I thought I found the answer by renaming Texture atlas_x.Png files to just Texture_0, 1 & 2 as they look identical to the ones Meshlab will read in....It did not work, maybe I'm barking up the wrong tree.  Thanks.

[hfcandrew]

You are making things waaaaaay more complicated than needed. Just clean up, orient, and scale the model in MM, export it in a file type your CAM can work with (.obj, .stl [binary or ascii]) and then just mill out the model directly. No need for anything else assuming im reading your post correctly and your end goal is just to mill something on a router.

What CAM software are you using?

Can you please attach your "Goddess post meshMix.obj"

[hfcandrew]

You are making things waaaaaay more complicated than needed. Just clean up, orient, and scale the model in MM, export it in a file type your CAM can work with (.obj, .stl [binary or ascii]) and then just mill out the model directly. No need for anything else assuming im reading your post correctly and your end goal is just to mill something on a router.

What CAM software are you using?

Can you please attach your "Goddess post meshMix.obj"

[MagWeb]

In addition to what Andrew said above:

A textured file ships with a geometry and an image information. A textured scanning result might mimic a better scanning result but for manufacturing purposes texture isn't that important.

A depth image takes the depth of the geometry only while the texture will be ignored. So it will not make any difference whether Meshlab is able to find the material definitions or not (although I'm not sure why this happens to you - here the texture handshake MM to ML works fine).

[MagWeb]

In addition to what Andrew said above:

A textured file ships with a geometry and an image information. A textured scanning result might mimic a better scanning result but for manufacturing purposes texture isn't that important.

A depth image takes the depth of the geometry only while the texture will be ignored. So it will not make any difference whether Meshlab is able to find the material definitions or not (although I'm not sure why this happens to you - here the texture handshake MM to ML works fine).

[Anonymous]

Hi Hfcandrew.

Thanks for the quick reply.

I use Fusion360 and also for quick tasks I use dmap2gcode which takes the png image from the  meshlab snapshot.

But, the actual OBJ  file still looks a bit rubbish when imported into F360, in fact it looks the same as the meshlab image, the face is 'lumpy'  and the body also. I was hoping that I could use the textured image from Meshmixer to create the final image, I thought(and am quite probably wrong) that the depthmap process basically applys a grayscale light level to the 3d image based on distance. So why can't the Textured image be used?

So, another question just to help me understand: I believe the texture overlays the mesh, so shouldn't the texture conform to the mesh?  Why are they so different. One is perfect, one is awful. How does the texture appear true but, the actual mesh is so different.

Maybe a good basic tutorial link could explain some of this, but having looked around, I never seem to come away with a 'Eureka' moment.

Cheers

[Anonymous]

Hi Hfcandrew.

Thanks for the quick reply.

I use Fusion360 and also for quick tasks I use dmap2gcode which takes the png image from the  meshlab snapshot.

But, the actual OBJ  file still looks a bit rubbish when imported into F360, in fact it looks the same as the meshlab image, the face is 'lumpy'  and the body also. I was hoping that I could use the textured image from Meshmixer to create the final image, I thought(and am quite probably wrong) that the depthmap process basically applys a grayscale light level to the 3d image based on distance. So why can't the Textured image be used?

So, another question just to help me understand: I believe the texture overlays the mesh, so shouldn't the texture conform to the mesh?  Why are they so different. One is perfect, one is awful. How does the texture appear true but, the actual mesh is so different.

Maybe a good basic tutorial link could explain some of this, but having looked around, I never seem to come away with a 'Eureka' moment.

Cheers

[Anonymous]

Hi Magweb.

I think I understand what you are saying. That the actual geometry is what is used for the cutting/milling process.

So, if I put a block of wood to machine and used the 'unsatisfactory' obj file, as the source file for the Gcode would it - when machined, look like the lumpy image as in Meshlab or the good image as per Meshmixer (I suspect lumpy).

The fact that you mention Meshlab pulls in the Meshmixer textured image successfully for you suggests something is not well with mine, I am using 'Meshlab_64bit_fp v2016.12'. I think this is still current - according to the update button. I shall have a look on the meshlab site to see if there is a cure for me there, thanks for that nugget.

[Anonymous]

Hi Magweb.

I think I understand what you are saying. That the actual geometry is what is used for the cutting/milling process.

So, if I put a block of wood to machine and used the 'unsatisfactory' obj file, as the source file for the Gcode would it - when machined, look like the lumpy image as in Meshlab or the good image as per Meshmixer (I suspect lumpy).

The fact that you mention Meshlab pulls in the Meshmixer textured image successfully for you suggests something is not well with mine, I am using 'Meshlab_64bit_fp v2016.12'. I think this is still current - according to the update button. I shall have a look on the meshlab site to see if there is a cure for me there, thanks for that nugget.

[Anonymous]

Sorry, missed your request. The  compressed file is still over 30mb, and my connection is pretty hopeless, if you would really want to see it I can upload it, but I wonder if technology would have moved on by time you received it.

[Anonymous]

Sorry, missed your request. The  compressed file is still over 30mb, and my connection is pretty hopeless, if you would really want to see it I can upload it, but I wonder if technology would have moved on by time you received it.

[Anonymous]

Sorry, not having a good day I'm replying to myself now! I missed your file request. The compressed file is still over 30mb, and my connection is pretty hopeless, if you would really want to see it I can upload it, but I wonder if technology would have moved on by time you received it.

[Anonymous]

Sorry, not having a good day I'm replying to myself now! I missed your file request. The compressed file is still over 30mb, and my connection is pretty hopeless, if you would really want to see it I can upload it, but I wonder if technology would have moved on by time you received it.

[MagWeb]

The output on a CNC will be the underlying geometry only - more or less like you see it in Meshlab.

In Meshmixer you can see it too using the default shader  (drag the grey sphere next to the plus from SHADERS onto the object) AND switch to rendering to FaceNormals mode (press Space on your keyboard  to open the Hotbox and in its Normals section click the button in the middle showing the facets on the sphere). That's the geometry which will be milled (without fancy rendering smoothing and texture).

Ad the Meshlab issue: Maybe the image file isn't at the right path. Open the .mtl in some text editor to see which and where the image is expected to be. Look for the lines starting with "map_Kd". If there's just a filename + suffix (e.g. something.jpg) the image needs to be in the very same folder as the .mtl. If there's some path+filename + suffix the image is expected to be over there.

[MagWeb]

The output on a CNC will be the underlying geometry only - more or less like you see it in Meshlab.

In Meshmixer you can see it too using the default shader  (drag the grey sphere next to the plus from SHADERS onto the object) AND switch to rendering to FaceNormals mode (press Space on your keyboard  to open the Hotbox and in its Normals section click the button in the middle showing the facets on the sphere). That's the geometry which will be milled (without fancy rendering smoothing and texture).

Ad the Meshlab issue: Maybe the image file isn't at the right path. Open the .mtl in some text editor to see which and where the image is expected to be. Look for the lines starting with "map_Kd". If there's just a filename + suffix (e.g. something.jpg) the image needs to be in the very same folder as the .mtl. If there's some path+filename + suffix the image is expected to be over there.