Thanks Marc, Very useful info.
Chris Morsel Animation ----- Original Message ----- From: "Marc Michael" <[EMAIL PROTECTED]> To: "Marc Michael" <[email protected]> Sent: Sunday, October 14, 2007 10:41 PM Subject: The best size for textures > Hello, > > ok, here we are. I have spend now some time to answer the question > "Which is the best size for textures"? And here is my answer. > > From a theoretical point of view I came to the following top 3: > > 1. The texture has the same size than the texture in the final > rendering. > 2. The texture is smaller than the texture in the final rendering. > 3. The texture is bigger than the texture in the final rendering. > > The number 1 is simply the best solution because you have full control > over every pixel in the image. Number 2 creates only a small amount of > distortions. But the final rendering can hold nearly all information > from the source texture. Number 3 is the worse! You will loose > information. It looks like cheese from Switzerland. It will have holes > in it. Think of what would happen if you have a texture of the size > 16x1 pixel which only consists of alternating black and white pixels > and you scale it down to a size of 8x1 pixels. Realsoft3D will create > 8 white pixels! This is the aliasing effect. Try to use a line drawing > as a texture in Realsoft3D. > > But from a practical point of view the top 3 turns around! > > To have the source texture the same size than the texture in the final > rendering isn't possible, simply because the texture in the final > rendering will be distorted by the perspective. The texture in the > final rendering will have different sizes at different locations in > the texture. > > If the source texture is smaller than the texture in the final > rendering than this will produce blocky images. Because there is no > information to fill the new pixels. So, many pixels will get the same > colour and the result is simply a blocky picture. > > The best solution is to create the source texture bigger than the > texture in the final rendering. But to prevent the aliasing effects > you have to scan it with a higher resolution. If the source texture > has more pixel than you use for scanning, this would result in > aliasing effects. This means, you have to use as much scanning rays as > your source texture consists of. For example, if your source texture > has a size of 5000x5000 pixels, you have to setup 5000x5000 scanning > rays to prevent aliasing effects, even when the texture in the final > rendering has a size of 500x500 pixels. This would waste a great > amount of CPU time. > > So, in my opinion the best solution is a source texture, which is > slightly bigger than the texture in the final rendering. After some > tests I came also to the conclusion that anti aliasing on the source > texture also helps to increase the quality of the texture in the final > rendering. > > I have setup a web page which I used as a scrap book: > > http://realsoft3d.turboland.de/BestTextureSize/ > > It's not finished yet, but it shows how I came to my opinion. I have > also done some real practical tests which doesn't shows up yet. > > Now it's your turn. What do you think? What's your experiences? > > -- > Best wishes, > Marc Michael > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.488 / Virus Database: 269.14.8/1064 - Release Date: 11/10/2007 15:09 > >
