שאלות ותשובות - Lab 3 Frequently Asked Questions - Lab 3 Вопросы и Ответы - Lab 3 أسئلة وأجوبة - Lab 3

		.. (לתיקייה המכילה)

		FAQ from this semster
	What does calculateIFSNormals do? add to 'normal' in the vr tree? replace it? How do we use/show normals per face? There is a mistake in the exercise definition - YOU DO NOT NEED TO DISPLAY NORMALS PER FACE. After running the two normal calculation functions all pervious data will be deleted. This means two things: 1) Do not run this function if normals per vertex are already given - there is a chance that the given normals are better than the calculated ones. 2) You do not have normals per face. Ever. But, when you send polygons to openGL without sending normals, they are automatically calculated per face, ONLY for backface culling, and not for shading, so you should take special care in order have flat shading. However, in this exercise we do not require that you implement flat shading. Is there a way to use backface culling for wireframe with OpenGL? Yes, there is. Do not use GL_LINE_LOOP, but draw polygons (GL_POLYGON, or GL_TRIANGLES) with the state: glPolygonMode(GL_FRONT,GL_LINE) In order to render full polygons again, use: glPolygonMode(GL_FRONT,GL_FILL) What is the best way to draw a background image in OpenGL? In my opinion, the best way would be using texture: What you want to do is draw a rectangle that will behind all the scene and will have exactly the size of the screen. On this rectangle add the background image as a texture, and walla - you get a background image. To find the right coordinates for this rectangle, I suggest you use gluUnProject

		FAQ from previous semesters
	How should I create the image for environment mapping? The best thing for you to do would be to render the scene without the object that would be textured. In order to get a good image, you should render the scene many times (for 360 degrees coverage) – and in each render take a small portion of it (for instance – the middle column) to the resulting image. There is no problem with the time it will take or if the screen will flicker in the process. After creating the image, use sphere_map to bind the image to the object.