Doom3world

Ive been doing a few expirements with grass in 3dsmax8 and getting some pretty convincing results.

I started by baking diffuse, specular, normal and ambient occlusion maps from high poly geometry to get the first layer; the underlying earth and leaves.
The earth is a flat plane with _d, _s and a bump map and the leaves are highpoly models also with the 3 maps applied.



After its been baked I use the earth and leaves texture for the base of the next layer where I placed models of grass, twigs, small weeds, and some less dead looking leaves to create a realistic looking ground texture, all these models have the 3 maps also.

I bake it for a second time. All the diffuse, specular and normal maps are combined and the ambient occlusion map is then multiplied onto the diffuse.



Wireframe.


One reason I baked it twice is because; If I dont divide up the work like this my pc will simply run out of virtual memory and grind to a halt, im sure alot of you have more up to date computers than I do so it may not be a problem.
Another reason is that I can build upon the leaves base texture multiple times to create many variants of ground textures to be used for vertex blended terrain and ultimatly megatexture.


Heres the final result in quake4, the textures are 1024, and Ive put a single light above where the player is standing in these pics, theres a few specular highlights which were put in unintentually but Ive grown to like them, it makes the grass look wet like a morning dew in low light conditions and they disapear when the lights are brighter.

so it's layers of grass/ground on top of each other in the level (physically on top of each other, like layers of patchs)? I did something similar in a Q4 CTF map I made a while ago. The results weren't bad but it still didn't look as nice as having grass stand up from the ground (ala Stalker or Serious Sam).

Still looks better then flat land though.

No, thats just one material, the layers I refered to were baked together in max, Ill still have to make some alpha planes for taller grass, but I think I wont need as much because of the amount of detail already in the ground material.
It definitly renders much better in a night time scene especially with a flashlight because all the normals adjacent to the player get lit up and that creates the illusion of them standing up strait no matter what direction they're veiwed from.

Those shots look nice, going to all the effort of modelling all the blades of grass definitely seems to have paid off in terms of the final normalmap.

looks great... maybe if you get some time you could make a tutorial on how it was done...

does look very good though.

If you combine the info in this thread with my baking multiple maps in 3dsmax tutorial you should be able to figure it out and there are plenty of tutorials out there about ambient acclusion.

But if you have any questions id be more than happy to help out.

ok thanks man,
i am going to try your tutorial now and see how i come along...

so that's only 1 layer of polygons? That's nice!

agreed, that's very impressive if that is the case

cheers for the feedback
I just got asked a few questions about making the grass and I thought that they might be useful here.



I found getting this texture to tile nicely quite tricky, If I had a more powerful machine I could have used 9 instances set up on a grid (3 by 3) and projected the centre one, if anyone has any ideas regarding that id love to hear them but heres how I did it;

Once I was happy with the grass I made a copy, (the grass is made up of lots of clumps of various shapes and sizes, and the other weeds are individual models aswell.)

I then selected all the models around the edges of the copy (all the ones that over lapped the edge of the projection plane) keeping locked to the grid, I then copied the models to their opposite sides.

if you check out step 4.4 of this tutoriayou should see what I mean, except in the case of the grass it must tile on both axis and it was a bit more fiddly because the models are more complex and there are more of them too.



theres no lighting setup at all, I rendered 2 ambient occlusion maps, one for each layer

Seems that it was quite a lot of work but I think it was worth it. And really nice that you explained a little of your workflow.

Wow, my eyes are having a hard time resolving this as a flat texture That looks wonderful!

There is an over-reliance on photo-wrapping everything these days, in my opinion. It can look great, but there's something to be said for how building assets up like this helps everything appear as if it is made from the same "stuff."

What's everyone talking about? Everyone's heard of this.... From what I'm seeing this just looks like information being baked onto a single polygon from a higher resolution model... Doom 3 can do this with Renderbump...

And I don't know about 3dsmax, but in Maya the grass and stuff can all be created very easily using Maya's Paint tools which allow you to paint a curve and apply objects to them, and later you can turn them into geometry if you like (which you would have to if you wanted to bake them into a material like this). What's really cool about this tool is that you could model your own 3d objects (more than one normally to create variation) then tell Maya you want your objects to be placed in Maya's Paint Tool Library, and you can paint your own objects instead of painting Maya's default load out (which are awesome without any custom addition anyway).

I'm not saying Mikebart did a bad job or anything, I think it was awesome he took the time to get this down but it's not THAT hard because I'm sure he didn't have to model every individual grass thingy. I just want to be clear I'm not trying to put someone's work down, but infact I think it looks really great and the result is better than I would've imagined, but it's not as hard as some people are making it out to be here.

Nice job though ^_^.

I don't think anyone is taking the process as some mystical new phenomenon, just admiring his execution of a known technique. It's also nice to see the process applied to something other than a modular sci-fi space station wall panel

What really struck me is it seemed some people thought he made every grass blade individually which was funny ^_^.

But agreed on the grass instead of sci-fi thing though.

Theres quite a big difference between the way im doing it and using renderbump in doom3.
Baking the diffuse and specular maps accuratly requires them being rendered to texture from the highpoly models, and rendering ambient occlusion maps are nesessary to blend the layers of diffusemaps. To my knowledge, Doom3 Renderbump is only useful for rendering normal maps but in saying that I really havent spent much time using it, so it may have other uses im unaware of.



I didnt actually state how I created the grass, their are countless ways one might go about making it depending on there modeling style and what 3d app they are using, but thanks for sharing that info on maya, im sure anyone using maya will find it useful.



Theres a good reason I post these ideas and its certainly not to accumulate fans wich I think is where you're going with some of these comments.
I post this stuff around several 3d forums in the hopes of getting criticism and advice to improve my workflow and skills, and it does.
I dont claim to know it all and I ask as many questions as any newbie would, if you've got some helpful suggestions I'd really love to hear them rather than these moot points you're making.



Well, im glad you found that amusing, lets just try and be real about this,
I've just read through the whole thread again and im looking hard to find any posts indicating that somebody thought I modeled each blade of grass individualy, thats just ridiculous Dinky
Think before you post man.

While renderbumpflat isn't anything new, the devil's in the details with this stuff. When you actually sit down and attempt to make one of these things- especially something unusual, you have to make a ton of little choices that make or break the final result. I think the big news here is using traditional photoshop/texture techniques like mirroring borders in a 3d modeling package. Also, using normal mapped geometry in your highpoly model adds another level of complexity that you haven't seen in quake4 or d3. I think the only packages that do this are maya and 3dsmax? I've never used lightwave's solution, but i know renderbump and modo don't.

Leads me to another question- your 3ds max normalmaps look great- i haven't had so much success in modo or maya generated maps, so i've been sticking to renderbump/flat, which means a lot of material writing while i'm working. Any idea why tangentspace maps vary so much?

I thought before I posted. Don't say crap again, and you definetly didn't read through the entire thread.

As for the rest of your post in reply to me, I haven't read it. No time, I only spotted this one at the end saying that I didn't think before I posted. I'm done with this thread now, because someone's had the raw brute lack of intelligence to insult me, so now I'm angry and if I continue this will probably turn into a flame post.

So I am done.... I SAID GOOD DAY!

Im not sure whether normalmaps were baked twice in doom3/quake4 like with the grass, but im pretty certain they were baking diffusemaps or atleast masks for some of the textures which is a pretty common thing, particularly some of the materials used in hell with the skulls and bones, bricks sticking out of the ground, that sort of thing, but this is really just speculation I find it pretty hard to tell how a texture's been made without seeing the workflow.

You're probably asking the wrong guy about why tangent space maps vary so much in different apps.
I never really got into using renderbumpflat and I haven't explored many other apps in terms of normalmapping. 3dsmax is all pretty automated as far as baking multiple bumpmaps and normalmaps go, I just drop textures into the map slots and they get rendered out, bumpmaps can be combined with RGBmultiply and some other procedural effects can be applied too, but I havent gotten much more advanced than that, its just something I haven't fully explored yet.
Render to texture in max is really quite simplified compared to some other apps, its not nearly as complicated as Zbrushes Zmapper which opens up a whole new level of complexity for normalmaps.

I swear, the next bloody person who overuses is going to die.

Here is my post:



Here is your post... (emphasis added by me)



Mikebart DID create a model with all the blades of grass, he just used shortcuts to do so, so learn some bloody reading comprehension before going off on a little whiny rant next time k?