Knowledgebase:POV-Ray Questions and Tips
Introduction
This document contains answers to frequently asked questions about POV-Ray as well as tips and tricks for various things. The collection was originally compiled by Warp as the POV-VFAQ (Very Frequently Asked Questions!).
If you have some question not answered here, don't be afraid to contact the TAG or ask in the appropriate group of the POV-Ray news server news.povray.org.
POV-Ray script language and rendering
Tips and tricks to achieve useful things:
- How do I make a visible light source? or: Although I put the camera just in front of my light source, I can't see anything. What am I doing wrong?
- How do I make bright objects, which look like they are emitting light?
- How do I move the camera in a circular path while looking at the origin?
- How do I use an image to texture my object?
- How can I generate a spline camera path for an animation?
- How can I simulate motion blur in POV-Ray?
- How can I find the size of a text object / center text / justify text?
- How do make extruded text in POV-Ray?
- How do I make an object hollow?
- How can I fill a glass with water or other objects?
- How can I bend an object, such as a cylinder, in POV-Ray?
- The focal blur is very grainy. Can I get rid of the graininess?
- Is blurred reflection possible in POV-Ray?
- I have really thin lines or very small details and I'm getting jagged lines and heavy moire patterns no matter what antialiasing settings I use. Is there any way of getting the best possible antialiasing, no matter how long it takes to render?
- How to repeat a cylindrical image map? New (21 Aug 2006)
Things that don't work as one expects:
- Even though I use bump mapping or specify a normal, I get straight shadow lines on my object. Why?
- I'm getting lighting artifacts in smooth meshes or heightfields near the borders.
- When I put several transparent objects one in front of another or inside another, POV-Ray calculates a few of them, but the rest are completely black, no matter what transparency values I give.
- When I make an image with POV-Ray, it seems to use just a few colors since I get color banding or concentric circles of colors or whatever where it shouldn't. How can I make POV-Ray to use more colors?
- When I rotate an object, it dissapears from the image or moves very strangely. Why?
- If I tell POV-Ray to render a square image or otherwise change the aspect ratio, the output image is distorted. What am I doing wrong? Updated (4 Feb 2006)
- Why are there strange dark pixels or noise on my CSG object?
- Why won't the textures in stars.inc work with my sky_sphere?
- Why doesn't my mirror reflect light? Why won't my lens focus light?
- When I use filter or transmit with my .tga image map nothing happens. Why?
- My isosurface is not rendering properly: there are holes or random noise or big parts or even the whole isosurface just disappears.
- When I scale something very large/small or locate something at very far distances the objects dissapear. What is causing this?
- Why doesn't #declare execute code each time?
- Sometimes when I use radiosity, I get big round artifacts in corners. What's wrong?.
- How do I turn animation on? I have used the clock variable in my scene, but POV-Ray still only calculates one frame.
- What is Photon Mapping?
- Can POV-Ray use multithreading and/or multiple processors?
- Is there a way to generate a wireframe output image from a POV scene file?
- Can I specify variable IOR for an object? Is there any patch that can do this? Is it possible?
- How do I use #while loops?
- Do I need inside_vector to use interior or media in a mesh?
Files and formats
- I have rendered an image with POV-Ray, but how do I save it to JPG or GIF or any other image format?
- Can I convert my POV-Ray scenes to another format?
- How can I convert my scenes from format X to POV-Ray format?
- How do I import all of my textures I created in 3DS Max into POV-Ray?
- How can I avoid artifacts and still get good JPEG compression?
- Why are there so many converters from other 3D file formats to POV, but practically no converters from POV to other formats?
- Why are triangle meshes in ASCII format? They are huge! A binary format would be a lot smaller. If POV-Ray can read binary images, why couldn't it read binary mesh data?
Utility programs, textures, models, etc...
- What is the best animation program available?
- How can I create/view mpeg-files in Windows/Linux/...?
- Where can I find models/textures to use in POV-Ray?
- What are the best modelers for use with POV-Ray?
- Are there any modelers for POV available on the Mac?
- Is there a user gallery of POV-Ray images somewhere?
- What's the best program to produce a height field for use with POV-Ray?
- Does anybody know an easy way to produce trees for POV-Ray?
Rendering speed
Miscellaneous
- I would like to suggest some new features for the program. Who should I talk to?
- When I render a height field I get lots of warning messages Illegal grid value in dda_traversal(). How can I correct that?
- How can I get rid of the beep after POV-Ray has calculated the image?
- Are there any POV-Ray viruses out there? Can one be done?
- I'm getting an error in Help file - contact your vendor error.
- Does POV-Ray for Unix have a GUI like in Windows?
- How can I set Moray to use the same handedness as POV-Ray? or: How can I set POV-Ray to use the same handedness as Moray?
- When I use an object created with Moray directly in POV-Ray, the object is mirrored. What can I do?
- How can I import my POV-Ray scenes into Moray so I can work on them in there?
- How do Moray UDOs work? Why don't they work for me?
Misconceptions
All of these topics may not be directly related to POV-Ray, but they are usually seen in POV-Ray (and rendering in general) related discussions.
- The high compression achieved by the JPEG format is achieved by dropping out unnecessary colors.
- Motion blur leaves a trace behind the object.
- Perspective doesn't affect a sphere. A sphere will always look circular.
- MegaPov's post-process focal blur is better and faster than POV-Ray's own, so the latter is not needed anymore.
- Why doesn't my mirror reflect light? Why won't my lens focus light?
- If I put my light source, which represent the Sun, at 150 millions of km away, it will give the most accurate result for sunlight simulation. Light rays coming from the Sun are parallel.
- Area lights are so slow in POV-Ray that it's much better to use a grid of point lights instead.
- About area lights in POV-Ray.