Re: [Pharo-users] Polygons in woden
Hi, sorry for the late response. Thanks a lot for the hints. Though I didn't explain me well enough for what concern the shades. What I actually meant is how light gets reflected from the object. If I build a cube with: addCubeWithWidth I get a nicely dark effect on the walls of the object when the light is not pointing to it and a shiny effect when the light is pointing towards to it. While if I build a object on my own with addQl the walls are not considering the light at all and I don't get that effect anymore. Does anyone know how to solve this? Moreover do you think it is possible to use some how GLPolygon to draw arbitrary polygons since woden is based on Open GL? Cheers, Nicolas. On Nov 9, 2014, at 11:12 PM, Ronie Salgado ronies...@gmail.commailto:ronies...@gmail.com wrote: Hi Nicola, Sorry for not answering before. I have to improve my mail filters. As for the shadows, currently only the spotlights can cast shadows. I have yet to implement shadow mapping for directional lights. As for point light, I won't be implementing them in the near future, because they are very expensive. Currently you can simulate a point light casting shadows by using 6 spotlights with different orientations but in the same point. Also, you have to use deferred shading if you need shadows (WDFPSSimpleExample8 #initializeSceneRenderer) As for the polygons, Woden cannot render arbitrary polygons. Only points, lines, triangles and quads because that is what the graphics cards support. For an arbitrary polygon, you have to perform some kind of triangulation. If the polygon is convex, this is trivial, but if the polygon is concave this is hard (the algorithm missing is a Restricted Delaunay Triangulation). For drawing a convex polygon, you have to do something like this: positions := Some Collection .. builder newTrianglesScope. Add the positions. positions do: [:i | builder addP: ]. Add the indices 3 to: positions size do: [:i | builder addI1: 1 i2: i - 1 i3: i ]. What this code does is to generate a triangle fan ( http://en.wikipedia.org/wiki/Triangle_fan ) which is a simple way to triangulate a convex polygon. I think that I should add a method to the geometry builder. Greetings, Ronie 2014-10-28 11:33 GMT-03:00 Nicolas Lusa nicolas.l...@usi.chmailto:nicolas.l...@usi.ch: Hi everyone, I am working on some 3d representation and I am trying to draw 3D polygons with woden. I actually manage to make the walls but I still have to implement top and bottom parts which are not so simple since the shape can be really different from case to case. How I am actually doing it is with: WDGeometryBuilder adding vertices with addP: N: C: TC: messages and with addQuadI1: i2: i3: i4: Furthermore I have some issues with the shadows which actually don't appear. You can see a current polygon created with the code that I made in the attached image. (also notice the shadows are missing as well as the bottom and top part of the polygon). [cid:E6905B6F-F5CA-447D-A42D-BA1604AC7F5A@mobile.usilu.netmailto:cid%3ae6905b6f-f5ca-447d-a42d-ba1604ac7...@mobile.usilu.net] Now my question is: is there already something that makes those polygons or does anyone have any hint on how to make the top part with woden? Thannks in advance. Cheers, Nicolas
Re: [Pharo-users] Polygons in woden
Hi Nicola, Sorry for not answering before. I have to improve my mail filters. As for the shadows, currently only the spotlights can cast shadows. I have yet to implement shadow mapping for directional lights. As for point light, I won't be implementing them in the near future, because they are very expensive. Currently you can simulate a point light casting shadows by using 6 spotlights with different orientations but in the same point. Also, you have to use deferred shading if you need shadows (WDFPSSimpleExample8 #initializeSceneRenderer) As for the polygons, Woden cannot render arbitrary polygons. Only points, lines, triangles and quads because that is what the graphics cards support. For an arbitrary polygon, you have to perform some kind of triangulation. If the polygon is convex, this is trivial, but if the polygon is concave this is hard (the algorithm missing is a Restricted Delaunay Triangulation). For drawing a convex polygon, you have to do something like this: positions := Some Collection .. builder newTrianglesScope. Add the positions. positions do: [:i | builder addP: ]. Add the indices 3 to: positions size do: [:i | builder addI1: 1 i2: i - 1 i3: i ]. What this code does is to generate a triangle fan ( http://en.wikipedia.org/wiki/Triangle_fan ) which is a simple way to triangulate a convex polygon. I think that I should add a method to the geometry builder. Greetings, Ronie 2014-10-28 11:33 GMT-03:00 Nicolas Lusa nicolas.l...@usi.ch: Hi everyone, I am working on some 3d representation and I am trying to draw 3D polygons with woden. I actually manage to make the walls but I still have to implement top and bottom parts which are not so simple since the shape can be really different from case to case. How I am actually doing it is with: WDGeometryBuilder adding vertices with addP: N: C: TC: messages and with addQuadI1: i2: i3: i4: Furthermore I have some issues with the shadows which actually don't appear. You can see a current polygon created with the code that I made in the attached image. (also notice the shadows are missing as well as the bottom and top part of the polygon). [cid:E6905B6F-F5CA-447D-A42D-BA1604AC7F5A@mobile.usilu.net] Now my question is: is there already something that makes those polygons or does anyone have any hint on how to make the top part with woden? Thannks in advance. Cheers, Nicolas
[Pharo-users] Polygons in woden
Hi everyone, I am working on some 3d representation and I am trying to draw 3D polygons with woden. I actually manage to make the walls but I still have to implement top and bottom parts which are not so simple since the shape can be really different from case to case. How I am actually doing it is with: WDGeometryBuilder adding vertices with addP: N: C: TC: messages and with addQuadI1: i2: i3: i4: Furthermore I have some issues with the shadows which actually don't appear. You can see a current polygon created with the code that I made in the attached image. (also notice the shadows are missing as well as the bottom and top part of the polygon). [cid:E6905B6F-F5CA-447D-A42D-BA1604AC7F5A@mobile.usilu.net] Now my question is: is there already something that makes those polygons or does anyone have any hint on how to make the top part with woden? Thannks in advance. Cheers, Nicolas
