Displacement Map - A Question

[samreay]

Hey guys,

 

I'm new to this forum and to Maxwell (a happy change from 3ds's normal mental ray render).

 

Ive basically been trying to create a patter on a surface using a displacement map, but so far Ive had no luck.

 

I have a good, 4000x4000 image, grayscale png (also tried it in jpg) and I know how to make materials and add things like a displacement modifier. However, problems run into each other at render time. Basically no matter what I do, what values I use for the displacement map, nothing ever happens when I try and render, my object stays completely flat.

 

Ive been trying to test this out on just a rectangular plane, and have used the image Maxwell provided as an example (so I KNOW it should work), but it doesn't seem to matter. Ive kept the plain as a simple piece of rectangular geometry, Ive tried subdividing into into 40000 segments (ie a plain with 200 heigh and width segments, created in 3ds Max 2009).

 

Ive managed to get a successful displacement when I've download premade scenes, but I cant ever get it to work on one of my own.

 

Does the object thats having the displacement map applied to it need to be a certain...something (Ive tried exporting it as a plain, an editable mesh and poly to no luck), or is there some trick that I dont know.

 

If anyone can lend a hand, share some tips, instructions or knows the location of a...comprehensive... tutorial I would be grateful.

 

Thanks

 

Sam

[amer abidi]

Check your global displacement settings in your render dialogue window.

 

I dont use maxwell, but thats the case with mental ray and many other renderers.

[Peter M. Gruhn]

I opened max, made a plane, set renderer to maxwell, opened the default mxm and applied it to the plane. Render. Looks good. Scroll the material down to displacement and stuck a preexisting splitface cmu bump map from another project in. Noticed that the displacement amount was "2" and decided to switch it to Absolute Height, 5cm to be sure it would show up. Render. Looks good.

 

I'll poke around some more and see if I can make it fail.

[Peter M. Gruhn]

I forgot, I also set precision to adaptive. Leaving it at 16 seriously degraded my results, smoothing them out some.

 

Just making sure... You are apply ing displacement by :

start with a maxwell material

scroll the material down to "displacement" and apply a bitmap to the texture slot

 

?

[samreay]

Its still not working (knowing my luck it never will )

 

Ill upload a screenshot of one of the the thing, basically just a plane exported from 3ds max and open in the maxwell studio.

 

Ive got the displacement map up on the window, and if put the result of a rendering on top of it as well. Basically I put the displacement map texture as the diffuse...woops maxwell talk..reflect 0 layer, using the same tiling parameters as in the displacement (didn't change any other values). Haha I've even rendered the underside of the plane to make sure it was displacing them downwards.

 

But yeah, you can see that in the material editor window, my preview of the material HAS got displacement! But it doesnt displace anything when I apply it to objects....argh...

 

Thanks for the quick reply guys, its much appreciated.

[Peter M. Gruhn]

Oops, sorry. I left the color and stuff panel open and I've gone and closed the scene already.

 

- made a plane in max. assigned a uvw planar fit

- export scene as 3ds

- open in maxwell

- open material, Default

- changed the colors

- found the "add displacement" menu item

- applied the material (not sure how, but it seems to have worked)

- rendered

 

and it worked...

 

What info didn't I give you... I don't think I changed the displacement settings in Maxwell. The plane was probably about 140" square with 4 segments each way. That jpeg I used is 640 x 480 and I poked at some of the buttons that looked interesting when I loaded it, but don't think I changed anything; particularly I left the tiling and realworld size (off) buttons alone. Looking back again at the settings in Maxwell I don't see any that I changed. I think I worried "how big is '2'?" but left it to see what would happen.

[samreay]

My good man, you have saved me.

 

I emulated your instructions perfectly, resigned to a failure, and rendered... slapped myself a few times to make sure I wasn't imagining anything, because...IT WORKED!

 

I've now fiddled around with just about every parameter to see why my others did not work (like the image has two planes, one with a UVW Map and the other without).

 

Finally I got a result, or moreso a lack of it. It turns out that you can only displace those objects exported under the 3DS option. I had previously been exporting it as a Maxwell Scene (MXS), which won't let you displace anything.

 

So thank you so much for helping those not as experienced.

 

Samuel

[Peter M. Gruhn]

> IT WORKED!

 

Hooray! And it looks like it worked pretty well too.

 

> I had previously been exporting it as a Maxwell Scene (MXS)

 

I've been doing a lot of OBJ exporting lately and saw that on the menu and thought to myself "I wonder how long that's been there." I do all my Maxwell rendering (such as it is, you may have noticed the demo watermark on my picture ;-) from inside Max.

 

> which won't let you displace anything.

 

Um... ... wow. I won't even pretend to understand why. You ran textures so it wasn't lost UVs. Internal geometry representation should be internal geometry representation no matter the source. I wonder if it breaks the scale maybe. Perhaps your MXS plane was 300 miles across being displaced 2". But if you weren't using absolute displacement should that matter (I don't know)? Be curious if you've any thoughts.

 

> thank you

 

My pleasure. So glad it worked.

[samreay]

Yeah it is a quite a weird situation. Fiddled around with scales and the amount of the displacement, it just appears that full stop displacement wont work.

 

Well, at least the 3ds programming technicians are still needed.

 

Thanks again

 

[fabbroc]

I did my own tests with Maxwell 2 and 3dsmax and what I learned is that it is not a problem with export format. Maxwell just does not like the max instances. When an object is instanced it will not do any displacement whereas when the object is not instanced it will do displacement. Simply delete the instances and Maxwell will work as expected.

 

Hope this helps

[samreay]

Do whats the trick then fabboc?

 

Heres exactly what I've done and it still wont work:

 

1. Open 3DS Max

2. Pull up material editor and load a displacement grass

3. Create a plane

4. Convert to edit mesh (only one plane, no instancing)

5. Made sure instancing option was disabled in render options

6. Render.

7. Fail.

 

Ive tried with a plane that has not been subdivided, and one that has been subdivided into more then 40000 polygons, but neither works (would it actually make a difference, can maxwell only manipulate faces with displacement, or should it work even if i made a plan that was had only one hieght and one width segment?)

 

The only way ive gotten it to work is by exporting to maxwell studio, which is a pain in the arse when im used to working in 3ds.

[Guest stol2004]

Im trying to render grass with displacement for a week ... I tried everything and still bad results ... my conclusion is that maxwell cant render grass like Vray does... I ve got a post on the forum with my ''best'' render result .. If u can do it better please let me know

[fabbroc]

Im not really sure whats going on then. Maxwell does have a new plugin for 3dsmax though. In the change log it said something about displacement

[samreay]

@fabbroc:

 

Yeah, I just updated the plugin to be the latest version, but still no luck. Its annoying because so many materials now use displacement mapping, and now they'll all look like shit.

 

@stol2004:

 

Okay, I would try using plane grass then, it looks better but is slower to render. A good tutorial is at the Maxwell Site under the top grass material.

 

Alternatively, to get your displacement grass working you need to:

 

1. Increase the tiling for you displacement and diffuse maps by a lot. Ie, make the images smaller so when the grass renders it doesnt look massive like yours does.

2. Change the displacement in the material to "Absolute Height", and find a value that works, depending on your scene scale this may go from 1 to 100 000. If your scene is actually in a 1:1 scale, try a value of 6.

 

Hopefully that should work, and (still hopefully), the grass will be small enough you shouldnt notice the seams in the texture.

 

Get back to me if you still cant get it to run properly.

 

Also if anyone can fix my displacement not rendering when I rendering Maxwell from inside Max.

 

Cheers

 

Sam

[Guest stol2004]

I managed to render FINALLY ! Looks like Maxwell doesn't like the triangles ... so i braked my surface in to quadrants and it worked pretty nice I say... Thnx for the tips anyway[ATTACH=CONFIG]36967[/ATTACH]

[samreay]

Glad you got it sorted.