3D_model_viewer.py

import pygame
import numpy as np
from pygame.locals import QUIT, KEYDOWN, KEYUP
from OpenGL.GL import *
from OpenGL.GLU import *

class Engine:
    def __init__(self, w, h,
                 fov=np.pi/4, near=0.1, far=100.0,
                 init_pos=None, init_yaw=-90.0, init_pitch=0.0):
        # Initialize Pygame + OpenGL context
        pygame.init()
        pygame.display.set_mode((w, h), pygame.DOUBLEBUF | pygame.OPENGL)
        pygame.display.set_caption("3D Renderer - Optimized")
        self.clock = pygame.time.Clock()
        self.w, self.h = w, h
        self.aspect = w / h

        # Camera parameters
        self.pos = np.array(init_pos if init_pos is not None else [-1.0, 5.0, 13.0], dtype=np.float32)
        self.yaw, self.pitch = init_yaw, init_pitch
        self._update_dir()
        self.speed = 0.1
        self.sensitivity = 0.1
        self.keys = {K: False for K in [pygame.K_w, pygame.K_s,
                                        pygame.K_a, pygame.K_d,
                                        pygame.K_SPACE, pygame.K_LSHIFT]}
        self.left_down = False
        pygame.mouse.set_visible(False)
        pygame.event.set_grab(True)

        # Projection matrix (once)
        glMatrixMode(GL_PROJECTION)
        glLoadIdentity()
        gluPerspective(np.degrees(fov), self.aspect, near, far)
        glMatrixMode(GL_MODELVIEW)

        # Enable depth and textures
        glEnable(GL_DEPTH_TEST)
        glEnable(GL_TEXTURE_2D)

        # Placeholder for display list and textures
        self.model_list = None
        self.texture_map = {}

    def _update_dir(self):
        ry, rp = np.radians(self.yaw), np.radians(self.pitch)
        dir_vec = np.array([
            np.cos(ry) * np.cos(rp),
            np.sin(rp),
            np.sin(ry) * np.cos(rp)
        ], dtype=np.float32)
        self.dir = dir_vec / np.linalg.norm(dir_vec)

    def handle_input(self):
        for event in pygame.event.get():
            if event.type == QUIT:
                pygame.quit(); quit()
            elif event.type in (KEYDOWN, KEYUP) and event.key in self.keys:
                self.keys[event.key] = (event.type == KEYDOWN)
            elif event.type == pygame.MOUSEBUTTONDOWN and event.button == 1:
                self.left_down = True
            elif event.type == pygame.MOUSEBUTTONUP and event.button == 1:
                self.left_down = False
            elif event.type == pygame.MOUSEMOTION and self.left_down:
                dx, dy = event.rel
                self.yaw   += dx * self.sensitivity
                self.pitch  = np.clip(self.pitch - dy * self.sensitivity, -89.0, 89.0)
                self._update_dir()

    def update_camera(self):
        forward = self.dir * self.speed
        right = np.cross(self.dir, [0,1,0])
        right = right / np.linalg.norm(right) * self.speed
        upv = np.array([0,1,0], dtype=np.float32) * self.speed

        if self.keys[pygame.K_w]: self.pos += forward
        if self.keys[pygame.K_s]: self.pos -= forward
        if self.keys[pygame.K_a]: self.pos -= right
        if self.keys[pygame.K_d]: self.pos += right
        if self.keys[pygame.K_SPACE]: self.pos += upv
        if self.keys[pygame.K_LSHIFT]: self.pos -= upv

    def set_camera(self):
        center = self.pos + self.dir
        glLoadIdentity()
        gluLookAt(*self.pos, *center, 0,1,0)

    def load_obj(self, obj_file, mtl_file=None):
        # Parse OBJ
        verts, texs, faces, face_mats = [], [], [], []
        current_mat = None
        materials = {}
        with open(obj_file) as f:
            for line in f:
                parts = line.split()
                if not parts: continue
                if parts[0]=='v': verts.append(list(map(float, parts[1:])))
                elif parts[0]=='vt': texs.append(list(map(float, parts[1:3])))
                elif parts[0]=='f':
                    idx = []
                    for v in parts[1:]:
                        vi, ti = v.split('/')[:2]
                        idx.append((int(vi)-1, int(ti)-1 if ti else None))
                    faces.append(idx)
                    face_mats.append(current_mat)
                elif parts[0]=='usemtl': current_mat = parts[1]
        # Parse MTL
        if mtl_file:
            mats = {}
            with open(mtl_file) as f:
                for line in f:
                    p = line.split()
                    if not p: continue
                    if p[0]=='newmtl': mat = p[1]; mats[mat]={}
                    elif p[0]=='map_Kd': mats[mat]['diffuse'] = p[1]
            materials = mats
            # Load textures
            for mat, data in materials.items():
                if 'diffuse' in data:
                    tex_id = self.load_texture(data['diffuse'])
                    self.texture_map[mat] = tex_id

        # Build display list
        self.model_list = glGenLists(1)
        glNewList(self.model_list, GL_COMPILE)
        glEnable(GL_TEXTURE_2D)
        for face, mat in zip(faces, face_mats):
            if mat and mat in self.texture_map:
                glBindTexture(GL_TEXTURE_2D, self.texture_map[mat])
            glBegin(GL_POLYGON)
            for vi, ti in face:
                if ti is not None and ti < len(texs):
                    u,v = texs[ti]
                    glTexCoord2f(u,v)
                x,y,z = verts[vi]
                glVertex3f(x,y,z)
            glEnd()
        glDisable(GL_TEXTURE_2D)
        glEndList()

    def load_texture(self, img_file):
        surf = pygame.image.load(img_file)
        data = pygame.image.tostring(surf, 'RGBA', True)
        w,h = surf.get_size()
        tex = glGenTextures(1)
        glBindTexture(GL_TEXTURE_2D, tex)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data)
        return tex

    def render(self):
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        self.set_camera()
        glCallList(self.model_list)

    def run(self, obj_file, mtl_file=None):
        self.load_obj(obj_file, mtl_file)
        while True:
            self.handle_input()
            self.update_camera()
            self.render()
            pygame.display.flip()
            self.clock.tick(60)

if __name__ == '__main__':
    init_pos = [0.0,2.0,5.0]
    e = Engine(800,600, init_pos=init_pos)
    e.run('Barbara.obj', 'Barbara.mtl')