sKulpt aims at being (someday J ) the modern reincarnation of the ancient but beloved Amiga 3D modeling and ray tracing software Sculpt Animate 3D / 4D by Eric Graham and Byte By Byte.

• Its modeling windows were compatible with RTG screens (Sculpt is restricted to PAL non-lace screens),
• It was compiled for the 68040 or the 68060, or even better the PPC, taking advantage of the orders of magnitude higher calculation speed of these processors over the 68000 and the 68020, the only two processors for which Sculpt is available on the Amiga,
• It used the 3D hardware available on the Amiga for a real-time preview,
• It enabled use of textures.

Don't try to run sKulpt if the Warp3D samples provided in the Warp3D user archive don't fully work. Among these samples, WarpTest provides an easy GUI to test many Warp3D features.

Warp3D should run under Picasso96, but I encountered some problems with this setup, so I can only say it works well with CybergraphX (which I advise running in its latest release, 4.2p7).

If you would like to run sKulpt without a 3D accelerated board, write to HAAGE & PARTNER saying you want to write the software renderer for Warp3D, and be prepared to code a pretty complex but very interesting piece of software.

• a hardware triangle rasterizer, i.e. a chip to which you pass the screen coordinates of a triangle, and which will render it filled with either pixels taken from a texture, or with colors shaded between its 3 vertices, or flat, or a mix of these. This task alone is a giant step from software rendering, many times faster than what you can achieve with even the fastest processors, thus even faster with Amiga processors. To put it in simple words, this is a part of the Video chip, which is able to fill a triangle alone, and ways faster than what you could do with program code.
• a hardware Z-buffer, which will draw a pixel only if it is "closer to the screen" than the pixel which is already at the same coordinates in its z-buffer memory. This enables easy removal of hidden surfaces, with almost no programming. Here again, an equivalent software process is simply coded, but orders of magnitude slower. You can even set the compare function (less, equal, more, etc.), z-buffer span etc.
• other fancy features like clipping, fog emulation, various blending functions etc.

• transform : the process of taking absolute 3D coordinates for triangle vertices and converting them to screen coordinates through a pipe of matrices (bone combination matrices, camera space projection and 2D projection)
• lighting : determining the amount of R, G, B for each triangle vertex, taking in consideration (among other parameters) the contribution of each light in the scene to the lighting of the vertex, modulated by the distance between the light and the vertex. Spreading these colors to each pixel in the triangle is left to the hardware (which linearly interpolates vertex colors, a process called Gouraud shading).

As you may have heard, on the PC platform, modern graphics boards like nVidia's GeForce ® © J take these two functions into hardware, thus freeing the processor for other calculations. At the time of this writing, this is not the case on the Amiga.

• a scene is a collection of meshes, edges, vertices and lamps (plus animation objects)
• a mesh is a collection of triangles
• a triangle is defined by 3 vertices (points in space), and a material
• a material is defined by its lighting and texture properties
• an edge is a segment between two vertices. Edges only serve for creating complex shapes by extrusion or helix replication etc. They are not rendered in the 3D view, since they have no surface.
• a vertex is a single point, which may be part of 0 to n edges, and of 0 to n triangles. Like edges, vertices by themselves are not rendered in the 3D view, since they also have no surface.

This is sufficient to create a 3D scene, which gets rendered as a 2D picture in the 3D view J

Able to load, view and rework Sculpt 3/4D scenes, except paths and object names. All the provided ".scene" sample scenes are actually original Sculpt 3D demo scenes. If you have a Sculpt scene which won't load in sKulpt, tell me.

Very sophisticated mesh triangulation engine, based on the Triangle project, supporting holes, optimization and more.

SKulpt offers various flexible ways to do the same thing. For instance :

If you feel it should be organized or illustrated in a different way, don't hesitate, tell me.

• 5 main windows : three 2D windows (top, face and right views), one 3D window, one trace window,
• a number ofdialog boxes, which are windows dedicated to a particular function, shown only while using this function,
• amenu, which enables command selection with the mouse.

The 2D windows represent the projection of your virtual 3D space along the 3 planes of a Cartesian coordinate system defined this way :

• face (X/Y) view :

• top (X/Z) view :

• right (Z/Y) view :

• the main cursor, which is the largest cyan cross surrounded by a yellow L shape. This shape materializes the influence zone of the current tool (when applicable). For instance, if the selector tool is the current tool, all vertices falling in the influence zone while moving the cursor will be selected. When a tool is selected, its reminding letter is present near the main cursor (it will be a 'S' for the selector tool).
• The two alternate cursors (small cyan X and cross). These alternate cursors ease the process of triangle creation, as if you hit the "create triangles" gadget or menu command, and there are no selected vertices, the system will create a triangle between the main and alternate cursors.
• The camera and view target (two white small V's) always linked by a white line
• The axes of the Cartesian coordinate system (gray lines). To remember which are the axes (X, Y, Z) of the 2D window you're looking at, they are indicated in the dark blue border of the window.

• Vertices (points in space) display as dots, which can be either black (not selected), or yellow (selected)
• Edges (lines between 2 vertices) always display red
• Triangles (between 3 vertices) display either pink or green (only one will be green, the one you currently work on when editing its material properties)
• Lamps display as small red V's, and one in the scene may display green, the one you currently work on when editing light properties

The 3D window will display the perspective view of the scene, seen from the camera position, looking at the target position.

• Their presence in the clipped view pane. As for the 2D windows, the 3D window only represents a part of the 3D space, projected in camera space. As with a real camera, everything not in the field of vision you just don't see. With sKulpt there is one more restrictions : triangles too close to the camera are not drawn (this is due to technical restrictions of underlying drivers, which tend to crash when drawing too close and large triangles). This enables a handy feature : when you come very close to convex objects, you can "see inside" as the closest faces of these objects are just not drawn, here is an example with a sphere :

• Their associated material, which cans either be flat or textured. Material properties are edited with appropriate dialog boxes, in which you define the color and texture material properties, with semantics identical to those of Microsoft's DirectX 7 (tech note : this is due to the fact that Warp3D does not provide any concept in the fields of lighting and materials, so as sKulpt is also developed on the Microsoft Direct 3D Immediate mode v7, I chose to port these concepts to the Amiga, as they suit well the purposes of both fast hardware assisted pre-rendering, and ray tracing). Material properties detail a material's diffuse reflection, ambient reflection, light emission, and specular highlighting characteristics. Material properties affect the colors SKulpt uses to rasterize polygons that use the material. Each of the properties is described as an RGBA color that represents how much of the red, green, and blue parts of a given type of light it reflects, and an alpha blending factor (the alpha component of the RGBA color). The material's specular property is described in two parts: color and power. For more information, see "Color Values for Lights and Materials" in the Microsoft DirectX 7 SDK documentation (the end of this paragraph is a reworked excerpt of it). Diffuse and Ambient Reflection properties describe how a material reflects the ambient and diffuse light in a scene. Because most scenes contain much more diffuse light than ambient light, diffuse reflection plays the largest part in determining color. Additionally, because diffuse light is directional, the angle of incidence for diffuse light affects the overall intensity of the reflection. Diffuse reflection is greatest when the light strikes a vertex parallel to the vertex normal. As the angle increases, the effect of diffuse reflection diminishes. The amount of light reflected is the cosine of the angle between the incoming light and the vertex normal. Ambient reflection, like ambient light, is non directional. Ambient reflection has a lesser impact on the apparent color of a rendered object, but it does affect the overall color, and is most noticeable when little or no diffuse light reflects off the material. A material's ambient reflection is affected by the ambient light set for the scene. Diffuse and ambient reflection work together to determine the perceived color of an object, and are usually identical values. For example, to render a blue crystalline object, you would create a material that reflected only the blue component of diffuse and ambient light. When placed in a room with a white light, the crystal appears to be blue. However, in a room that has only red light, the same crystal would appear to be black, because its material doesn't reflect red light. Emission can be used to make a rendered object appear to be self-luminous. The Emissive property is used to describe the color and transparency of the emitted light. Emission affects an object's color and can, for example, make a dark material brighter and take on part of the emitted color. You can use a material's emissive property to add the illusion that an object is emitting light, without incurring the computational overhead of adding a light to the scene. In the case of the blue crystal, the emissive property could be handy if you wanted to make the crystal appear to light up, but not actually cast light on other objects in the scene. Remember, materials with emissive properties don't actually emit light that can be reflected by other objects in a scene. To achieve this effect, you would need to place an additional light within the scene. Specular Reflection creates highlights on objects, making them appear shiny. You establish the color of the specular highlights by setting the specular property to the desired RGBA color—the most common colors are white or light gray. The values you set in the Power property control how sharp the specular effects are. Specular highlights can create dramatic effects. Textures are bitmaps mapped to the triangles, like if they were painted onto them. For instance, in the following picture, you see the same scene, left rendered as wireframe to show the triangles, and right rendered as full faces. It displays a textured tiger standing on a flat blue Gouraud shaded triangle (light is on the right of the scene) :

• Their light exposure. In all cases, sKulpt applies Gouraud shading. When sKulpt renders a polygon using Gouraud shading, it computes a color for each vertex by using the vertex normal and lighting parameters. Then, it interpolates the color across the face of the polygons. The interpolation is done linearly. For example, if the red component of the color of vertex 1 is 0.8 and the red component of vertex 2 is 0.4, utilizing the Gouraud shading mode and the RGB color model, the lighting module would assign a red component of 0.6 to the pixel at the midpoint of the line between these vertices. The following figure demonstrates Gouraud shading. This teapot is composed of many flat, triangular polygons. However, Gouraud shading makes the surface of the object appear curved and smooth :

The trace window displays either informative messages, or error messages (if you ask for something impossible like creating a triangle with only 2 vertices, or if sKulpt encounters an internal error).

1. The loader of Sculpt original files does not load paths nor name hierarchies. Everything else is loaded (vertices, edges, triangles, lamps, observer & target position etc.). The loader does not erase existing entities in memory, but rather adds the contents of the file to the existing scene. All dimensions of objects in the file are scaled to fit within the current window dimensions. At the moment, sKulpt is not able to save original Sculpt files.
2. The loader for ".x" DirectX object files does not load animation sets. All hierarchies are melted into the scene (i.e. you loose mesh / frame decomposition). The X loader does not support binary files, but only the text variant. If you want to load binary X files, please use the converter provided by Microsoft to convert them to text files. The X loader does not support pre-defined meshes and materials then referenced by their names (although this feature is often used in X files). This will be available in later releases, as well as a converter from animation sets into sKulpt paths. Please note that everything is erased prior to loading an X file, which is a different behavior from the original Sculpt loader. The native sKulpt format (".sk3d") loader acts as the X file loader, that is it erases all before loading. The X file format does not include camera / target / lamp definitions. Thus, camera / target location is not affected by loading an X file, and you may have to add lamps to "see something" in the 3D window after loading an X file.
3. The saver for ".x" DirectX object files is far from complete, it is just a quick hack which should generate files that can be loaded with the Xfile viewer on the PC side. The saver does not generate files that can then be re-read by sKulpt (it will come later). At the moment, the format of choice (and the only format indeed) to load and save scenes is the native sKulpt format, ".sk3d" (which is an IFF format btw).
4. The "Résumé" option puts the number of vertices, triangles, edges, lamps, materials etc. present in the scene. As sKulpt works with static tables, these tables may fragment as you delete entities, and in this case the "frag %" will not be 0 for the various entities. If you want to "garbage collect", or reorganize the tables to speed up things, you may enter the "!" command, which will do this automagically for you.
5. Erasing vertices will also erase the edges or triangles which the vertices were part of.
6. Erasing edges will leave the vertices untouched.
7. Erasing triangles will leave the vertices untouched.
8. Edit materials brings the following requester to the screen, leaving you play with the various attributes of the materials :

   

   The top slider enables choosing the material you are working on. The first 5 materials (# 0 to 4) can not be deleted. Apart from this, all materials can be fully edited.

   The Diffusion sliders let you adjust the RGBA properties of diffusion light properties for the material. See the lighting engine for additional info, and play with this to discover its use. Note that diffuse properties only show under light exposure, apart from the A which defines the A for the whole triangle.

   The Ambient sliders let you play with the RGBA properties. They define the way the object "exposes" the ambient light definition made with the "Monde > Illumination globale" menu.

   The Emission properties define the way the faces will emit light, i.e. they will seem lighted from the inside.

   The Specular properties define the way the faces will "shine".

   Notes : at the moment, the A components of Ambient, Emission and Specular are ignored. The Specular properties are also ignored.

   The Name is the material name, which you can fully edit up to 80 char.

   The Texture radio button and slider will let you choose whether this material is textured or not, and which texture will be mapped.

   The OK button lets you validate all your changes. The Annuler (cancel) button will let you cancel the changes you made on the current material and close the requester. The Restaurer (restore) button will let you cancel the changes made on the current material without closing the requester. The Nouveau (new) button will let you duplicate the current material into a new one. The Supprimer (delete) button will let you delete the current material.

9. Edit Faces will bring the following requester :

   

   The purpose of this dialog is to enable you to choose which material is applied to the selected faces, and if the material is texture mapped, how the triangles project onto the texture.

   When you enter this dialog, both the 2D and the 3D views get redrawn, and the triangle face on which you are currently working is outlined with a green line.

   You can go to the 2D windows to move the target / camera while editing faces, so that you can always pick the best point of view.

   In the dialog, the "<" and ">" let you navigate among the selected faces.

   The top slider lets you choose the material to apply to the current face.

   If the material is texture mapped, you will see the texture image drawn (like the above).

   You can set the U/V (texture projection coordinates) for each of the 3 triangle vertices with the 1, 2, 3 horizontal & vertical sliders.

   You can also premap the triangle to one of the 4 corners of the texture using the 4 small buttons above the U/V coordinates. These buttons cycle through the various combinations of 3 vertices to 3 texture corners.

   The replicate button will spread the current face settings to all the selected faces, without affecting the destination face's U/V.

   The replicate + button will also affect the U/V.

   The OK button closes the dialog.

   The other controls are not active at the moment.

    

   Edit Lamps will bring the following requester :

   

   This will let you edit the lamp properties. If there is no lamp in the scene, you won't have access to this requester. Otherwise, you can choose the lamp to edit using the top slider. The currently edited lamp gets drawn in green in the 2D windows.

   The Diffuse / Ambient / Specular RGBA properties speak for themselves, give a look at the lighting engine chapter.

   The other properties are lit / unlit, lamp type (point / spot / directional), the 3 distance attenuation coefficients, the range, falloff, teta and phi parameters.

   In the current release, the spot / directional types are not implemented, and the range, falloff, teta and phi parameters are ignored.

10. The expand / reduce command will bring the following requester :

    

    These commands only apply to the selected entities. The X/Y/Z factors speak for themselves ; the top radio button lets you lock the proportions. The Apply / reset buttons let you either apply the changes to the selection, or come back to the original settings, without closing the dialog. The OK / Cancel buttons do the same, closing the dialog.

11. The Fill command invokes the mesh triangulator. You must select a set of closed curves prior to invoking this command. The triangulator will try to arrange a set of triangles which fit in the curves, which are defined by vertices of the curves. This helps creating arbitrary shapes.

    Here is a curve before and after triangulation :

     

    This is a very powerful feature, saving hours of work, particularly combined with extrusion. Here is the above triangulated curve extruded a bit :

    

    Note that the edges are not removed from the curve (so that you can reuse them). You can remove them by the "edit > remove selected edges" command.

    This feature supports holes and more, but at this moment, the hole definition procedure is not available on the Amiga. Although I am not able to test this, I guess you should use a standard math library setup otherwise the triangulator may crash, as it is very sensitive to accuracy. If it crashes, it will give you an error message that you should report to me.

12. The Replicate on helix command is also very powerful. It enables quick creation of translated AND / OR rotated clones of the selection.

    The dialog lets you choose whether the clones will be linked or not, if the clones are to be rotated and / or translated, the translation and rotation axes (which are smartly preset according to the 2D window which is active when you invoke the command), the angle in degrees per rotation step, the advance per translation step, and the number of steps.

    Here is a sample of a curve, rotated and not translated to produce a glass shape :

     

    Here is a sample of a triangle, both translated and rotated, to create a stairs shape :

    

    Here is a sample of a cube set, translated and not rotated, to create a brick wall shape :

    

13. The smooth / unsmooth faces command is only working in the PC version by now. I am not certain how I will implement this on the Amiga, Warp3D being unaware of normals (in other words, I have to handle per vertex normal calculation by myself L ).
14. This command will do nothing if there are neither 2 nor 3 selected vertices. Otherwise it will add an edge (2) or a triangle (3).
15. This command will add a sphere, bringing a requester in which you can set the number of slices. The revolution axis is normal to the 2D window which was active when you invoked the command.
16. Same as above, for an hemisphere.
17. Same as above, for a torus.
18. The boing ball has its properties pre-defined.
19. N/a
20. The prism is a cone with 4 vertices at its base. The revolution axis is normal to the 2D window which was active when you invoked the command.
21. A requester asks for the number of slices. The revolution axis is normal to the 2D window which was active when you invoked the command.
22. Same as above.
23. Same as above.
24. Same as above.
25. Same as above.
26. The main cursor will be centered to the unweighted average center of the selection.
27. The main cursor will be centered to the closest grid step.
28. This command is a toggle for grid activation. Grid introduces steps for the cursor locations, in both X/Y/Z axes. It helps creating vertices which are part in multiple triangles, for regularly shaped objects. Note that sKulpt has a smart feature which determines if it should consider two vertices as the same and when to do so.
29. The selector tool is reminded by an 'S' next to the main cursor. Its influence zone is the yellow square around the main cursor.
30. Same as above. The unselector's letter is 'U', and the influence zone is black.
31. The curve tool lets you create free connected edge suites, otherwise named as curves. To create a point in the current curve at the current main cursor location, press 'p' or click the '…' window gadget. To finish the curve without closing it, simply select no tool (or press space). To finish the curve closing it to its first point, press 'q' or select "curve > finish". Take care to what is selected at the end before extruding or grabbing.
32. See above.
33. The extruder tool creates a clone of the selection, linked to the selection, selects the clone, and selects the grabber tool. When you then drag the main cursor, you will see an elevation of your original selection. To unselect the grabber tool, either press space or select the "Tool > none" menu command, or click on the grabber icon (the lower left 2D window gadget).
34. The grabber tool lets you move all the selected vertices (the edges and triangles will follow). To unselect the grabber tool, either press space or select the "Tool > none" menu command, or click on the grabber icon (the lower left 2D window gadget). Take much care in what is actually selected when you use the grabber tool (even what you don't see because of panning and zooming). There is currently no way to put things in their original location. This also applies to the extruder tool, which is a special form of the grabber.
35. The show points or edges commands let you reduce the time necessary to update the 3D view, by rendering only the vertices or triangle edges. It is also a creative tool. See the tiger sample above. Note : on the Permedia2 chip, the points and lines are fully textured, while on the ViRGE chip, the points and lines are only Gouraud shaded.

• : rotate counter-clockwise or clockwise. This command only applies to the selected vertices (of course, the edges and triangles they take part in will follow). This command also accepts keyboard modifiers : clicking it while the left Shift key is pressed will double the angle (normally 1/40^th a turn, 1/20^th when shifted).
• and its 3 brothers : pan the visible "window". The 3D space is projected onto the plane associated to each 2D window ; the 3D space is not finite in size, and you only see a small rectangle window in this projection. You can move this window with the 4 pane gadgets. The 2D windows are displaying the same 3D cube, so when you pan in any direction in any 2D window, the other windows will "follow". This process is a but strange in the beginning, but anyone should quickly accommodate.
• : center the 2D views on the main cursor position
• and : add points and edges / triangles. You can add points anytime. Adding edges and triangles is done the following way : if there is no selected vertices, a triangle is added between the 3 cursors. If only one vertex is selected, nothing is done. If 2 vertices are selected, an edge is added between them. If 3 vertices are selected, a triangle is added between them. If more than 3 vertices are selected, nothing is done.
• : this is the grabber tool de/activator. When you click it, it toggles the grabber tool. When the grabber tool is active, it displays as a 'G' near the main cursor ; all relative moves of the main cursor (when you drag it in a 2D window) will be applied to the selected vertices (and of course, the edges and triangles they take part in will follow). Sample pictures above show this : on the left, we just activated the grabber, and on the right we moved it up a bit ; only the yellow vertices have been affected :

• and : zoom in / out. Same principle as panning.
• : I've forgotten about this one. It was in the original Sculpt, but I don't remember its use, and live without it. If anyone wants something useful, just ask.

• Add a freeware raytracing engine, which would start working in the background as soon as the 3D scene is rendered, stop working as soon as anything is modified in the scene, and overdraw the 3D window with the raytraced image if it could complete rendering before something has moved in the scene.
• Add more input/output file formats, maybe through a 3D file Datatype class system to be developed
• Finish the smart texture pre-mapper (planar, spherical, cylindrical)
• Animation support
• Light properties editor
• Full normal vectors based Gouraud support
• Font outline support in Amiga version
• Hole support when filling curves in Amiga version
• Texture blending / Alpha blending in Amiga version
• Splitting Intuition message handling into a 68K task to speed up GUI in PPC Amiga version
• Localization (never gave a look at this...)
• Finishing the serious chapter of the documentation

• Binaries 68k
• Binaries PPC
• Binaries x86
• Sources 68k / PPC
• Sources x86

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• My wife for her supporting many Amigas and other computers at home, their fans whirling late at night, my children & family for the love they give everyday,
• The ones who made the Amiga what it is now and which I really LOVE : the perfect nerd platform !
  Hardware : Commodore original design team, special mention to Dave Haynie, VillageTronic, Phase 5, GVP, Janal crew
  Software : authors of the jewels : MUI, MCP, SAS/C, Aztec C, Storm C, WarpOS, Warp3D, Picasso96, Cybergraphics, NetConnect, AmiTCP, Miami, IBRowse, Yam, AmIRC, Microdot, MakeCD and a few other
• The Janal crew who undisclosed this platform to me
• Gilles Roy and David Larochette for the ideas and code
• Steffen Haeuser, Sam Jordan, Frieden brothers and Mr. Haage for their support and high quality software they bring to the Classic Amiga. Support them, they are among the very rare !
• Jonathan Richard Shewchuk for his Triangle mesh-triangulation suite, which is a lesson in good C programming as well as the perfect fit to my curve filling needs
• Microsoft for the Direct3D v7 SDK, a jewel for understanding 3D programming. You Amigans, before smashing this file because I mention the Redmond firm, go have a look !
• The 3D chipset manufacturers and gaming industry for having brought the fast hardware 3D features to our desktops at affordable prices : S3, nVidia, 3Dlabs and so on
• Others I forget but will recognize themselves for sure !