Hello,
I am using Blender 2.49B and I have just finished reading the book “Bounce Tumble and Splash” by Tony Mullens. Which is an excellent book and I learnt a lot.
What I want to know is on the DVD there are a number of Maps for using with the Ivy Generator. What I want to know is how the maps were made? Can they be made with Blender? I have attached some of them as an example.
Thanking you in anticipation.:eyebrowlift:
You want to know how the diffuse texture map and normal map is made?
You need a leaf, a photo camera, preferably 5 pictures, gimp and xNormals.
Take 4 photos from 4 directions and use xNormals to calculate the normal map.
Take 1 top picture and edit it in gimp for the diffuse map.
combine them on a plane in blender.
job done.
Arexma, a more thorough explanation of what you just described might be very beneficial to a lot of people (both now and in the Google future…). Let’s say that we are not using Gimp. What does “xNormals” actually do? If we actually wanted to follow in your footsteps and edit in gimp for the diffuse map," what would we actually have to do?
“Details… details… AtDhVaAnNkCsE” (“thanks in ADVANCE”)
Yah well, assuming thats what the OP meant, here we go 
If that´s not sufficient I do a full tutorial on request.
A Small tutorial for making leaf textures:
Introduction:
You´ll need a camera - any does the job, even a cellphonecam does it nowadays, you might want to have somthing with a flashlight though unless you got a lightrig.
You´ll need some kind of battery powered point light source, or you take the leaves home with you.
GIMP - free image manipulation tool (any other does too that can work either with transparency or alpha channels)
xNormals - google for it, it is a powerful free tool for normal map generation either from images or high poly geometry
Shutdown your computer and leave the house with or without a camera, don´t forget to dress and prepare yourself for social interaction - if you fail to do so you got to get a life we´ll cover that in another howto
Go and gather some leafs, real ones from plantlife and bring them home.
You now got 2 options to take the images, you make only one image for the diffuse texture map and make a “fake normalmap” out of a “fake heightmap”, or you do the whole procedure for high quality normal maps.
Prepare:
As a leaf usually is green, try to find some blue towel, paper, sheet whatever.
If you don´t want to use the flashlight you´ll need a lightcube or a lightsetup to prevent shadows for the diffuse image.
If you want to do a high quality normal map you need a camera tripod of some kind.
Step 1.a- diffuse texture:
Simply take the picture of the leaf and get it on your computer. Be sure to have a nice lighting and almost no shadows. You either need a small lightcube, a light setup, or take the picture with a flash.
Many digital cameras got a nice preset for taking macro images of plantlife with softflash. Should work nice.
We don´t want to have shadows actually because the texture will get a normal map and the shadows should be cast by the geometry lateron in the scene. If you don´t want to do a high quality normal map, you can skip step 2
Step 1.b - high quality normal map:
Setup your camera with a tripod above the leaf, neither the camera, nor the leaf should move for the next 5 images, you could also align the images lateron in GIMP if you got no tripod and want HQ normal maps.
Take the first image like in step 1.a just with the tripod to be sure nothing moves, else you got to align everything lateron.
Now for the following images it is imperative you take them without flashlight. You´ll need your pointlight here, the color quality of the images is secondary.
If you look down on your leaf, put the pointlight “north” of the leaf so it is outside the image and the shadows are cast to the south, take image 1.
Now continue with east, south, west so you got 4 images casting shadows. Those will be used to calculate normal maps. In short, a algorithm will detect the edges in the image and in regards of the shadowlength it is able to calculate back on the geometry.
Remember that you need 4 images for this process.
Step 2 create the diffuse texture:
Download and install GIMP if you got no image manipulation tool, it is free.
Open up our picture from Step 1. Naturally the image comes with no transparency, also the file has none yet.
First step, use the rectangular select tool <R> and once you started to drag hold down <shift> so it maintains a 1:1 proportion, make a nice selection just around the leaf.
Now press <shift>+<ctrl>+<c> or go to Edit>copy visible
Now press <shift>+<ctrl>+<v> or go to Edit>paste as>new image
Close the original photo and save your new image(s).
Now on the right you see the layer management rightclick your layer and choose “add alpha channel” or go to Layers>Transparency>Add alpha channel
As first step you want to resize the image now to your designated texture size. Usually powers of 2 because UV mapping and memory managment works best with it, not going there now. So 128x128, 256x256, 512x512, 1024x1024 - you want to choose a higher one, because you can always shrink the texture lateron but you can´t make it bigger later without loosing quality unless you redo it.
Now we got to get rid of the background. If you had a blue or really different colored background you can use the magic wand tool - or fuzzy select tool as it is called in GIMP, by pressing <u> or selecting it from the toolshelf.
Be sure to select [x] feather edges and set it to 2-5px in the tools options.
Now click in the blue background and DO NOT release the button. You´ll notice it selects most of the blue background but maybe not nice around the edges of the leaf. Move your mouse up and down (forward and backward, in any case, don´t lift it ) and you´ll notice it selects more or less of the same color. That is how this tool works. It selects similar colors. As our leaf is green and blue is a color that not really is present in a leaf it is easy for the tool to select all the blue.
Once you are happy with the selection, just press <del> (not backspace, delete)
Now the blue should be gone, you should have a feathered (blurred and not pixelated outline) leaf that is sitting on a gray checkerboard, which shows transparency.
If you are unhappy with parts of it, use the eraser tool or select tool to clean it up.
If you can´t use the fuzzy select for some reason, you got to cut the leaf out manually, you use the “lasso tool” called free select tool in gimp, and cut around the leaf. Once the selection is closed, you press <ctrl>+<i> to invert the selction, as you currently have the leaf selected and press <del> again to delete the background.
Last but not least, safe your new texture. You got to safe it in a format that supports transparency. I usually use .png for compressed textures, if I need them uncompressed I usually use .tga.
Give it a nice name you´ll recognize lateron like “ivy_leaf_diffuse_map_1024.png” for a 1024x1024 texture.
Step 3.a: Create normal map from 1 image:
With your image still open, make it grayscale - desaturate it: Colors > Desaturate
Now open up Colors > Levels. You´ll see 3 small triangles blow the top graph, move them around till your image looks something like this:
High areas almost white, lowest areas almost black.
You got to judge what is supposed to be high and low on the image and use the middle triangle to have an even color distribution.
Once happy, apply it and save the image again as “ivy_leaf_heightmap_1024.png”
Now open up xNormals, which you downloaded and installed earlier obviously.
Under Tools you´ll find “Height map to normal map” open it.
righclick in the left window, open the heightmap, righclick in the righ window and press generate.
Your fake normalmap is done, save it “ivy_leaf_normal_map_1024”
Step 3.b: Create HQ normal map from 4 images:
This one takes some preperation again if you didn´t work feral and the images are aligned already.
You´ll have to fit your 4 images to match the diffuse image in position and size. If they don´t match already, do so by opening them in one file with layers as done before, and turn down the opacity slider for the 4 layers and move/scale/rotate them until they match the diffuse image. Once done, turn opacity back to 100% and save all 4 images.
Now it´s time to fire up xNormals. For this use tools> PhotoNormal.
The interface is pretty self explainatory. You got 4 slots where you rightclick and load the 4 images “left-lit, right-lit, top-lit and bottom-lit photo” then you righclick in the right slot and press generate.
And it will calculate your normal map. Save the image and fire up blender.
In blender create a plane.
Go in edit mode, select the plane, be sure you are viewing it from the top, press <u> and choose “project from view (bounds)” this will cause the UV coordinates to match your coming up texture.
Add a new material, turn on z-transparency and turn the material alpha and specular in the transparency settings down to 0
Go to the texture tab and add a new image texture.
Choose the diffuse texture, set it the mapping coordinates to UV, under image check [x] premultiply (it will premultiply the alpha and prevent white jiggy lines around the leaf)
and in influence check Color and set it to 1.0 and Alpha and set it to 1.0
If you render your plane now you should already see a nice leaf with transparency. Now we need to add the normal map.
Add another texture, choose image, map to UV coordinates.
This time under image sampling select [x] normal map then the dropdown selection below will ungray and you´ll be able to select it. Set it to “tangent”. This means the normal map will affect the tangent space of the object, it will manipulate the existing normals of the object with the ones from the normal map.
Under influence be sure to turn off color as we don´t want the normal map to be seen, we just want it to affect the normals, so under Geometry check [x] Normal and leave it to 1.0. It does not matter what you set here, you can´t change the depth of a normal map due to its matrix nature. The slider is there because you also use it to add heightmaps, and you can change the magnitude of them with the slider.
If your normal map doesn´t show the deisred effect you can either try to enhance it playing with the normal maps contrast, or redo the normal map calculation.
If your viewport supports GLSL and you switch to textured mode you´ll see instant feedback on your leaf. If all is just black, you´ll need to add a light to your secene
hth
Thank you arexma for such a detailed reply I shall have a go at that. :yes:
