Is it possible to generate a hight map from objects?

[pixelplucker]

I am wondering if I could generate a height map from objects in a scene. What I want to ultimately do is create one grayscale image that can be used as a displacement or height map.

 

I have a small laser engraver that seems capable of carving from grayscale images into various materials such as wood, plastic etc. I'm also thinking of doing carvings to make molds from for pewter castings.

 

Thoughts?

[robcat2075]

You mean A:M objects, right?

 

One way is to take the depth buffer that A:M can render in OpenEXR format and scale/clip that in a paint program to extract teh range you need for your object inthe scene.

 

You can also do that in A:M

 

http://www.hash.com/forums/index.php?showt...p;hl=extracting

 

 

If the objects you want to convert to grayscale map are all in one model you could apply a white to black gradient material on them and render that inthe model window.

[pixelplucker]

I couldn't seem to get the depth buffer to see differences on the mesh itself but only as silhouettes of each object in the scene. I wanted to be able to create a bas relief from objects and then cut them.

 

Am I doing something wrong?

[robcat2075]

I couldn't seem to get the depth buffer to see differences on the mesh itself but only as silhouettes of each object in the scene. I wanted to be able to create a bas relief from objects and then cut them.

 

Am I doing something wrong?

 

Possibly, but note that depth map details are typically very subtle shades of gray. I do know that OpenEXR depth buffer do work correctly and my gradient material technique also works, having used it in the past to make displacement maps..

 

I'd have to see your non-working example to know more.

[zandoriastudios]

Color all of your objects white, flat shaded, then render with black camera fog

[pixelplucker]

Depth buffers do work! I remember in the previous version they just produced a silo of the objects.

 

I couldn't get the fog to work since lights interfered with the render and not sure if fog works with an ortho camera.

 

For the depth buffer I needed to invert the image and clip the threshold to the image got gain the most range. Just need to test it on my laser next.

 

If all works well I should be able to produce masters for molding easily from a composition of models as well as some cool wood carvings etc. Lots of fun.

 

Original model is an stl. Seeing that is is possible to do this through AM opens up a lot more flexibilities since I can just plob shapes together and not have to fiddle fart with open surfaces etc.

 

Thanks!

[robcat2075]

Last I tried, Fog and orthogonal views don't work together.

[pixelplucker]

Fog could be a good technique for composing scenes that ortho would normally make look lousy.

[robcat2075]

You can use an extremely long focal length camera which will look almost the same, but for my depth mapping purposes i found the gradient material pretty much got me what i wanted with an orthogonal camera.

[pixelplucker]

I couldn't seem to get the gradient material to map correctly on the stl, probably because it has no uv coordinates. Might work fine on an obj though.

[pixelplucker]

Laser is cutting 3d from the image pretty well, I need to muck around with the speed, wattage and stepping but looks pretty cool from defaults. I'll post some picks when I get my scanner hooked back up.

 

Big thanks!

[pixelplucker]

I just found an OpenEXR converter that will produce basic bmp files or what ever format you may want to convert it to...

http://www.xnview.com/en/xnconvert/

 

I have been parsing out the exr to multiple layers (Robcats suggestion) and carving them on my laser engraver.

The people that made the driver software for the laser added a new function to simply input the number of passes for a set grayscale height map. This feature was only available on the $50,000+ machines but now is available on the desktop models > $1,500.

[robcat2075]

How many layers do you regard an EXR file to be for that purpose?

[pixelplucker]

Lasers don't use exr but can import common formats such as gif, bmp, png and jpg so basically they can only use 255 levels max.

I suppose you could make a scene, render out an exr, convert it to a bmp and use it as a displacement map on models. Anyways that converter is free and has batch capabilities. Just something I thought others could find useful.

[robcat2075]

255 sounds like it would be disappointingly coarse.

[pixelplucker]

Actually not since most laser carvings are well under 1/4" which would translate to .00098". Smaller step than a 3d print.

Half that set on an item that has a 1/8" deep carving.

 

This is ideal for lapel pins, challenge coins, key chains etc.