May 12

Texturing 1000 trees with one texture

The Problem:

Often, in aerial renders we have the problem of having 1000s of different trees that all look the same. Now, the solution for the most realistic result would be to have 1000 different textures and texture each of those 1000 different trees individually… Unfortunately deadlines, time lines and my sanity dictate that that’s more than a little unreasonable!

Another solution would be to randomly select some of the trees, have a couple of textures set up and texture just a few of the trees differently. While that’s a good solution, it’s hardly ideal because you’ll still have trees that look similar.

The Solution:

Enter SCREEN MAPPING!

Simply put, screen mapping stretches an image across the entire screen, effectively projecting the image OVER your geometry.

Here is an example that makes it quite clear. The geometry is all 3D with a VRay Sun.

The integrity of the image and the locations of each pixel is kept intact, BUT because of the 3D geometry, it still receives shadows, reflections and is effected by GI.

Using screen mapping for all of our trees, we can project an image of a forest over our trees, giving each tree a unique colour.

Using the Screen Mapping method, we can change ALL of our trees by only changing 1 texture. So changing this scene radically, to Autumn, is easy…

Another benefit is that the effect can be as pronounced or as subtle as you want it.

Here are some examples where we’ve used Screen Mapping in our production work:

Something important to remember is that this technique CANNOT BE USED IN ANIMATION. Your texture will remain static while your image moves.

Happy texturing.

By Chris B

Comments - No registration needed

Edward Peinke May 12th

Wow.. what a simple fix that seems to work really well.. thanks!!
art May 13th

So is this a plugin or a trick in max, I still don’t understand how you do that, please explain or supply a link to where to buy this plugin.

Thanks,

A
Chris B May 13th

Hey Art, its a trick in Max.

In your MATERIAL EDITOR, there are different ways to apply mapping to an object. Under your COORDINATES dialog, there are two options, TEXTURE, and ENVIRON. TEXTURE applies to treating each objects co-ordinates as unique to that object, while ENVIRON applies to using the ENVIRONMENT to gain texture coordinates.

Select ENVIRON, and you have SCREEN, SPHERICAL, CYLINDRICAL, and SHRINK WRAP. Selecting screen is what gives you this effect. It really is as simple is clicking over one tab (from Texture to Environ).
Philip May 13th

I am right in saying you still need to have the trees in so the polygone count it still very big?
and your mapping the texture over the trees.

So still not clear, is there more to this tutorial, like can you show with out the forest and then with?

Thanks though

phil
Nic B May 13th

Phil, its more of a texturing trick – so that all the trees dont look the same, think of it as applying an image map blanket over the entire forrest.
Simon May 13th

Cool. You could also use that bitmap, or noise, mapped to World XYZ to introduce some variety. This has the advantage of working in animations too. I use one blended with a texture for leaves close up. Great work in your portfolio by the way, congrats!
James Shaw May 13th

Hey Chris,

Nice tutorial. You could actually use this technique for animation, just use the camera map modifier…

- Pick the trees and add a camera map modifier, then select your camera you’re using for the scene.
- Change your texture from environ/ screen to texture/ normal explicit map channel
- Animate the camera and the texture will stay fixed on the frame you set the camera map modifier on.
Bina May 14th

Just have in mind that this kind of mapping is NOT fully compatible with reflections…
Tom Svilans May 14th

If you were to set up camera projection from a couple of angles, to cover all the trees from some different angles, couldn’t you use it for animation as well? Say if the projection cameras stayed put, but you just moved a different camera, sort of like view-based UV mapping…

Don’t have 3ds MAX but I’m gonna give this a shot with Blender…
mindymind May 14th

how does the texture looks like? just crowns?
awesome May 14th

lame! might be cool if it worked for animation, but you can just do this with a render pass and photopshop in probably the same amount of time it takes to set this up.

right!?
Chris B May 17th

Hey Simon-thanks! Ill try that out and see how I go with it. I’m also doing some playing around with using vertex mapping to get variation in texturing grass.

James & Tom -I never considered using Camera Mapping with this! I’ve never had much luck with Camera Mapping and the VRay Camera, (I think its the vertical shift that MAX’s camera projection doesn’t like). Ill try out some tests, and amend the tutorial if I can get it to work.

Bina, I haven’t encountered issues using this with my reflections. Id be interested to know what the issues are, and if you have found any workarounds?

mindymind, I’m not sure I understand your comment..

awesome, No, you couldn’t do this in a Photoshop pass. Well, you possibly could, but it would require a separate depth, MAT ID, and shadow pass, comped together with the texture, and even then you wouldn’t get the texture effecting GI, or reflection/refraction.
The time this takes to set up is literally changing the mapping from TEXTURE to ENVIRON, and applying the texture.
Tumelo May 28th

Interesting!