[Josephus Holt]

I want to make a displacement map for a tile roof, I have a section modeled the way I want it. Someone suggested using planar mapping to add the black & white gradient to the model, I've got that, but don't know how to get a very high quality top axonometric view image off that (I'm using Rhino, and have no other renderer than the basic Rhino (or c4d) render engine and Maxwell). I'm able to get a pretty decent result with just using the screendump image and then boosting to 16bit in photoshop...but seems a bit like trying to do fine woodwork with a chainsaw

[dmeyer]

Why not just render the geometry, using instances if necessary? Converting to Displacement is going to increase render time many fold...

[Josephus Holt]

Why not just render the geometry, using instances if necessary? Converting to Displacement is going to increase render time many fold...

That's what I did, but since this is my first exterior Rhino/Maxwell render....all 5,000+ roof tiles are modeled geometry, but I'm starting to come up to my 12gb ram limit, and still need to do all my landscaping (learning as I go). I could go back and redo all using instances (the roof tiles are all not all uniform, but tweaked slightly for a more natural look), but this would take some time to do, but remains an option. In some tests I saw that the benchmark dropped dramatically when using displacement...as they say, I'll have to pay somewhere, either up front with redoing all with instances or do it quickly now with displacement but pay later with looooong render time.

[tom]

You don't really need to map it. Put the camera above in a distance and render zBuffer. That will give you a decent displacement map. You can use clipping planes to find out the suitable range. Check > http://think.maxwellrender.com/zbuffer_ ... ue-70.html

[Josephus Holt]

You don't really need to map it. Put the camera above in a distance and render zBuffer. That will give you a decent displacement map. You can use clipping planes to find out the suitable range. Check > http://think.maxwellrender.com/zbuffer_ ... ue-70.html

OK thx Tom. Time to learn the zbuffer channel...thought there might be a better way No sound for the movie, right?
So I can do this inside of Rhino but just keep the camera distance far enough so the very minimal perspective distortion becomes a non-issue?

[Bubbaloo]

So I can do this inside of Rhino but just keep the camera distance far enough so the very minimal perspective distortion becomes a non-issue?

I've done it this way before.

Also, you may try to render out a top view from Studio. Haven't tried that one yet.

[tom]

So I can do this inside of Rhino but just keep the camera distance far enough so the very minimal perspective distortion becomes a non-issue?

Exactly!
Btw, I don't think top view will work due to range.

[Josephus Holt]

Thx much Tom, that worked really easy and fast too! Great result, runnning a test now, looking good

By the way, that DOES work for me in Studio in the top view as well, just kept the same camera height and zbuffer near and far plane settings. Actually, what I SHOULD say is that I also did a render out of the top view with the same settings, but have NOT confirmed that it is 100% axonometric....maybe this weekend I'll verify.

Is there a way to know what values MW used when the setting is to adaptive? Isn't it better to set a specific value for the displacement precision?

[Bubbaloo]

If it's an object that will not be seen close up, you can get away with setting the displacement lower to speed up rendering. Adaptive will set it as high as the map resolution will allow.

[Josephus Holt]

If it's an object that will not be seen close up, you can get away with setting the displacement lower to speed up rendering. Adaptive will set it as high as the map resolution will allow.

So to find the optimum manually set value for precision is trial and error? Probably would not take much to figure out. Will run some tests in the next few days to see the effect on the benchmark.

By the way, I confirmed that the top view in Studio works with using zbuffer settings, provides a perfect axonometric view for the displacement map.

[tom]

So to find the optimum manually set value for precision is trial and error? Probably would not take much to figure out. Will run some tests in the next few days to see the effect on the benchmark.

Yes, but it's not that trial and error. When you know your mesh density and texture resolution, it's not hard to find an efficient value. Please check manual page 71.

By the way, I confirmed that the top view in Studio works with using zbuffer settings, provides a perfect axonometric view for the displacement map.

That's great, I just haven't tried it myself. Probably, it works because the object is on the axis plane.

[Josephus Holt]

So to find the optimum manually set value for precision is trial and error? Probably would not take much to figure out. Will run some tests in the next few days to see the effect on the benchmark.

Yes, but it's not that trial and error. When you know your mesh density and texture resolution, it's not hard to find an efficient value. Please check manual page 71.

I actually read that page earlier this morning and came to that conclusion. I'm running a few tests to find the minimum value that will produce satisfactory results...I'm looking right now at an adaptive setting giving me a benchmark around 47 and if I set the precision manually to 500 (texture map is approx 500x500 and I exported a single quad poly) , then I get a benchmark in the 260's.

[osuire]

I'm trying to use the Z-buffer technique to create displacement maps, but I have trouble setting the near and far distances.
Since the camera needs to be very far from the object to avoid perspective distortion, and the depth variations on my object are rather small, I can't seem to find the right values...

Cheers,

--
Olivier

[Bubbaloo]

You can determine distances by switching to a perspective view (other than your camera view), and use the visual display of the z-clip parameters. Transfer those to your z-depth settings.

Since the camera needs to be very far from the object to avoid perspective distortion

By the way, I confirmed that the top view in Studio works with using zbuffer settings, provides a perfect axonometric view for the displacement map.