Modelling a gravestone

[Alex _Legg]

Hi guys,

I'm after some advice please.

I have to create several tombstones for a client.; The basic shape is simple (a rectangle with a curved top), but they have intricate carvings of leaves and a relief of a face with wings on the top, as well as the actual text on the tomb.

The client initally wants a hi res version to use for a trailor, and has said to 'model everything'. The problem I have is how to do these intricate details, especially the text itself. Because there are obviously a lot of rounded letters in the text, I can't really make the topology match the shapes. I've used a stencil to produce the text, and even subdivided to over 3mil polys, the text is still jagged.



So can anyone advise me how they would do this?

Am I best to accept that I cannot model the text, and just create a normal map instead?

Also does anyone have any suggestion on how to do the intricate carvings (leaves and a relief of a face with wings), as I'm assuming I'll run into the same problem!


Many thanks

Alex

[Hulahuga]

Use a stencil for the carvings, It should work. Make sure that you've densified the high detaild areas before subdividing ;).

[aphexx]

you can solve this in several ways.
but i think the best way would be:



create an B/W image with the text in photoshop and be sure its at least a 16 bit per channel picture. best would be 32 bit per channel..
thensave it within a 32 or 16bit capable format (tiff or exr perhaps..but cs3 cannot save exr i think..)
in mudbox subdivide you mesh to at least 6 million polys. 3 million could be too less.
import your text as a stencil and use it on your stone with a normal sculpt brush. (set the spacing to zero)

that should do the job i think..

you could also try to give your stone a uv layout, and then paint a diplacement for it, and then "maps"->"sculpt model from displacement map"

to avoid errors just be aware of the uv boundaries..dont come near to them with any uv element!t 4 pixels away from the border because of edge beeding. otherwise you will get errors and loose time!

[Wayne]

Just paint a bump map for the text details, you could create the text as a stencil in photoshop and image project this into your bump channel.

The decoration does depend on the type and density of it. If your talking heavy baroque style you could simply work out your main shapes *even pencil them in on a temp texture layer) then just refine as you step up your levels using the flatten and scrape brush to give those edges you need.


Wayne...

[Alex _Legg]

Thanks for the feed back guys, its sooo good to get others perspective on things.

I think using over 6mil polys, would be too much for my system, and probably too high res!

So as I suspected, it'll probably have to be the bump map/normal map.


A question on the bump map though, when I take the model back to 3DS Max, do I still use the bump map, or am I better to convert it into a normal map? - As I understand it, normal maps are better than bump?!

Alex

[Alex _Legg]

Here is a photo of some of the graves they want modelling, as I said nothing too complicated...

But on seeing this, does anyone have any additional comments on how they would go about doing it?


Thanks

Alex

http://www.alex-legg.co.uk/pics/IMG_0723_small.jpg

[Wayne]

Well not every model needs a normal map. In a case such as this as a bump would suffice along with any displacement. My rule of thumb is to never make things any more complex than they need to be at render time.

Wayne...

[RobinB]

I reckon you're probably best off leaving the text off the sculpt and just making it in Photoshop as a displacement map to add at render time.

Here's a quicky test.

It's just a text layer in Photoshop rasterised and blurred so the edges aren't sharp. You could probably get a decent chamfered cut in using layer effects. Then it's added to a simple one segment plane using displacement. I had to set the displacement to a fairly high level to avoid jagged edges but as it's only done on the bucket level at render time it doesn't need much memory (this work machine only has 2 gig and it was fine for the render).

If you need to combine this with the displacement from the sculpture I assume that'd be easy enough although that's outside my usual workflow.

The advantage of using displacement over bump or normal maps is that the cut in text can be quite deep and can cast and receive shadows. That might not be necessary for those gravestones though unless the camera gets near.

[aphexx]

for what do you need those stones?
will the camera ever get so near to them? are they "hero" objects or just of secondary interest?
or are they for a game?

in this case you could even go for a normal map done in photoshop from a 2d image with the nvidia plugin..i wrote a tutorial about this. (http://saschahenrichs.blogspot.com/2008/10/normalmap-creation-with-photoshop-and.html)

for hero objects, i'd still try the stencil option in mudbox.
anyway cool texture work is needed.

[Alex _Legg]

Thanks guys,

Aphexx, the models are for a game trailer, they want hi res, but they will only be secondary (but they were keen on everything being modelled. They'll probably be doing the low res version and textures themselves (although I may also do them for my portfolio!)


Robin, thanks for taking the time to do a test. That looks really impressive. Last time I used displacment maps I remember it being a bit of a faff and not getting great results. Time I revisited them I think...

Alex

[RobinB]

All I did for the displacement in that shot was to change the Edge Length setting in the mental ray global displacement options to 0.25 pixels. It was even better at 0.1 pixels, but that was slower. I think it defaults to 2 or higher.

It's not totally smooth, but probably smoother than you can get in Mud without using loads of subdivisions.

Another way of doing it might be to do an old game trick of having the plane with the text on seperate to the gravestone and floating in front of the main gravestone object. Then you don't need to subdivide the whole gravestone to get more resolution out of the part with the text. When you generate the displacement map make sure to include the plane and make it render to the furthest surface. I can't remember off the top of my head whether this will work for displacements but it can do for rendering normal maps.

[Alex _Legg]

Thanks for all the help Robin.

I had already tried th floating plane trick, but at 3 mil it was still too low res!

The displacment map looks good though. I've not been able to get any work done this weekend yet, but will have do some sxperimenting when I can.

Alex